diff --git a/web/src/compose_actions.js b/web/src/compose_actions.js
index daa8c99e70..9892b87986 100644
--- a/web/src/compose_actions.js
+++ b/web/src/compose_actions.js
@@ -119,7 +119,10 @@ export function complete_starting_tasks(msg_type, opts) {
 
     maybe_scroll_up_selected_message();
     compose_fade.start_compose(msg_type);
-    stream_bar.decorate(opts.stream, $("#stream_message_recipient_topic .message_header_stream"));
+    stream_bar.decorate(
+        opts.stream_id,
+        $("#stream_message_recipient_topic .message_header_stream"),
+    );
     $(document).trigger(new $.Event("compose_started.zulip", opts));
     compose_recipient.update_placeholder_text();
     compose_recipient.update_narrow_to_recipient_visibility();
@@ -153,7 +156,7 @@ export function maybe_scroll_up_selected_message() {
 function fill_in_opts_from_current_narrowed_view(msg_type, opts) {
     return {
         message_type: msg_type,
-        stream: "",
+        stream_id: "",
         topic: "",
         private_message_recipient: "",
         trigger: "unknown",
@@ -171,7 +174,7 @@ function same_recipient_as_before(msg_type, opts) {
     return (
         compose_state.get_message_type() === msg_type &&
         ((msg_type === "stream" &&
-            opts.stream === compose_state.stream_name() &&
+            opts.stream_id === compose_state.stream_id() &&
             opts.topic === compose_state.topic()) ||
             (msg_type === "private" &&
                 opts.private_message_recipient === compose_state.private_message_recipient()))
@@ -216,7 +219,7 @@ export function start(msg_type, opts) {
         (opts.trigger === "new topic button" ||
             (opts.trigger === "compose_hotkey" && msg_type === "stream"))
     ) {
-        opts.stream = subbed_streams[0].name;
+        opts.stream_id = subbed_streams[0].stream_id;
     }
 
     if (compose_state.composing() && !same_recipient_as_before(msg_type, opts)) {
@@ -227,12 +230,12 @@ export function start(msg_type, opts) {
     const $stream_header_colorblock = $(
         "#compose_select_recipient_widget_wrapper .stream_header_colorblock",
     );
-    stream_bar.decorate(opts.stream, $stream_header_colorblock);
+    stream_bar.decorate(opts.stream_id, $stream_header_colorblock);
 
     if (msg_type === "private") {
         compose_state.set_compose_recipient_id(compose_recipient.DIRECT_MESSAGE_ID);
-    } else if (opts.stream) {
-        compose_state.set_stream_name(opts.stream);
+    } else if (opts.stream_id) {
+        compose_state.set_stream_id(opts.stream_id);
     } else {
         // Open stream selection dropdown if no stream is selected.
         compose_recipient.open_compose_recipient_dropdown();
@@ -361,11 +364,11 @@ export function respond_to_message(opts) {
         msg_type = message.type;
     }
 
-    let stream = "";
+    let stream_id = "";
     let topic = "";
     let pm_recipient = "";
     if (msg_type === "stream") {
-        stream = message.stream;
+        stream_id = message.stream_id;
         topic = message.topic;
     } else {
         pm_recipient = message.reply_to;
@@ -380,7 +383,7 @@ export function respond_to_message(opts) {
     }
 
     start(msg_type, {
-        stream,
+        stream_id,
         topic,
         private_message_recipient: pm_recipient,
         trigger: opts.trigger,
diff --git a/web/src/compose_recipient.js b/web/src/compose_recipient.js
index 66e9ec92ac..72e3bd2bf3 100644
--- a/web/src/compose_recipient.js
+++ b/web/src/compose_recipient.js
@@ -153,7 +153,7 @@ function switch_message_type(message_type) {
 
     const opts = {
         message_type,
-        stream: compose_state.stream_name(),
+        stream_id: compose_state.stream_id(),
         topic: compose_state.topic(),
         private_message_recipient: compose_state.private_message_recipient(),
     };
@@ -162,8 +162,8 @@ function switch_message_type(message_type) {
     compose_ui.set_focus(message_type, opts);
 }
 
-function update_recipient_label(stream_name) {
-    const stream = stream_data.get_sub_by_name(stream_name);
+function update_recipient_label(stream_id) {
+    const stream = stream_data.get_sub_by_id(stream_id);
     if (stream === undefined) {
         $("#compose_select_recipient_widget .dropdown_widget_value").text(
             $t({defaultMessage: "Select a stream"}),
@@ -182,7 +182,7 @@ export function update_compose_for_message_type(message_type, opts) {
         $("#stream_toggle").addClass("active");
         $("#private_message_toggle").removeClass("active");
         $("#compose-recipient").removeClass("compose-recipient-direct-selected");
-        update_recipient_label(opts.stream);
+        update_recipient_label(opts.stream_id);
     } else {
         $("#compose-direct-recipient").show();
         $("#stream_message_recipient_topic").hide();
@@ -220,9 +220,9 @@ export function on_compose_select_recipient_update() {
         const $stream_header_colorblock = $(
             "#compose_select_recipient_widget_wrapper .stream_header_colorblock",
         );
-        const stream_name = compose_state.stream_name();
-        update_recipient_label(stream_name);
-        stream_bar.decorate(stream_name, $stream_header_colorblock);
+        const stream_id = compose_state.stream_id();
+        update_recipient_label(stream_id);
+        stream_bar.decorate(stream_id, $stream_header_colorblock);
     }
 
     check_posting_policy_for_compose_box();
@@ -351,7 +351,7 @@ export function update_placeholder_text() {
 
     const opts = {
         message_type: compose_state.get_message_type(),
-        stream: compose_state.stream_name(),
+        stream_id: compose_state.stream_id(),
         topic: compose_state.topic(),
         // TODO: to remove a circular import, direct message recipient needs
         // to be calculated in compose_state instead of compose_pm_pill.
diff --git a/web/src/compose_state.js b/web/src/compose_state.js
index c4d9eca5f8..bb80a28a66 100644
--- a/web/src/compose_state.js
+++ b/web/src/compose_state.js
@@ -1,9 +1,7 @@
 import $ from "jquery";
 
-import * as blueslip from "./blueslip";
 import * as compose_pm_pill from "./compose_pm_pill";
 import * as compose_recipient from "./compose_recipient";
-import * as stream_data from "./stream_data";
 import * as sub_store from "./sub_store";
 
 let message_type = false; // 'stream', 'private', or false-y
@@ -88,20 +86,7 @@ export function stream_name() {
     return "";
 }
 
-export function set_stream_name(stream_name) {
-    if (!stream_name) {
-        compose_recipient.set_selected_recipient_id("");
-        return;
-    }
-
-    // If we fail to select a stream that the caller expects
-    // us to do successfully, we should throw an error.
-    const stream_id = stream_data.get_stream_id(stream_name);
-    if (stream_id === undefined) {
-        blueslip.error("Unable to select stream: " + stream_name);
-        compose_recipient.set_selected_recipient_id("");
-        return;
-    }
+export function set_stream_id(stream_id) {
     compose_recipient.set_selected_recipient_id(stream_id);
 }
 
diff --git a/web/src/compose_ui.js b/web/src/compose_ui.js
index 73c9064a23..8acc0d3630 100644
--- a/web/src/compose_ui.js
+++ b/web/src/compose_ui.js
@@ -11,6 +11,7 @@ import * as loading from "./loading";
 import * as people from "./people";
 import * as popover_menus from "./popover_menus";
 import * as rtl from "./rtl";
+import * as stream_data from "./stream_data";
 import * as user_status from "./user_status";
 
 export let compose_spinner_visible = false;
@@ -35,10 +36,10 @@ export function autosize_textarea($textarea) {
 
 function get_focus_area(msg_type, opts) {
     // Set focus to "Topic" when narrowed to a stream+topic and "New topic" button clicked.
-    if (msg_type === "stream" && opts.stream && !opts.topic) {
+    if (msg_type === "stream" && opts.stream_id && !opts.topic) {
         return "#stream_message_recipient_topic";
     } else if (
-        (msg_type === "stream" && opts.stream) ||
+        (msg_type === "stream" && opts.stream_id) ||
         (msg_type === "private" && opts.private_message_recipient)
     ) {
         if (opts.trigger === "new topic button") {
@@ -224,13 +225,16 @@ export function compute_placeholder_text(opts) {
     // because the caller is expected to insert this into the
     // placeholder field in a way that does HTML escaping.
     if (opts.message_type === "stream") {
-        if (opts.topic) {
+        const stream = stream_data.get_sub_by_id(opts.stream_id);
+        const stream_name = stream ? stream.name : "";
+
+        if (stream_name && opts.topic) {
             return $t(
                 {defaultMessage: "Message #{stream_name} > {topic_name}"},
-                {stream_name: opts.stream, topic_name: opts.topic},
+                {stream_name, topic_name: opts.topic},
             );
-        } else if (opts.stream) {
-            return $t({defaultMessage: "Message #{stream_name}"}, {stream_name: opts.stream});
+        } else if (stream_name) {
+            return $t({defaultMessage: "Message #{stream_name}"}, {stream_name});
         }
     }
 
diff --git a/web/src/composebox_typeahead.js b/web/src/composebox_typeahead.js
index 1e67e58c32..f8d06acfb7 100644
--- a/web/src/composebox_typeahead.js
+++ b/web/src/composebox_typeahead.js
@@ -436,7 +436,7 @@ export function get_pm_people(query) {
     const opts = {
         want_broadcast: false,
         filter_pills: true,
-        stream: compose_state.stream_name(),
+        stream_id: compose_state.stream_id(),
         topic: compose_state.topic(),
     };
     return get_person_suggestions(query, opts);
@@ -509,7 +509,7 @@ export function get_person_suggestions(query, opts) {
     return typeahead_helper.sort_recipients({
         users: filtered_persons,
         query,
-        current_stream: opts.stream,
+        current_stream_id: opts.stream_id,
         current_topic: opts.topic,
         groups: filtered_groups,
         max_num_items,
@@ -520,14 +520,14 @@ export function get_stream_topic_data(hacky_this) {
     const opts = {};
     const $message_row = hacky_this.$element.closest(".message_row");
     if ($message_row.length === 1) {
-        // we are editing a message so we try to use it's keys.
+        // we are editing a message so we try to use its keys.
         const msg = message_store.get(rows.id($message_row));
         if (msg.type === "stream") {
-            opts.stream = msg.stream;
+            opts.stream_id = msg.stream_id;
             opts.topic = msg.topic;
         }
     } else {
-        opts.stream = compose_state.stream_name();
+        opts.stream_id = compose_state.stream_id();
         opts.topic = compose_state.topic();
     }
     return opts;
diff --git a/web/src/drafts.js b/web/src/drafts.js
index 4fa863669b..02e08700b4 100644
--- a/web/src/drafts.js
+++ b/web/src/drafts.js
@@ -360,9 +360,14 @@ export function format_draft(draft) {
                     draft_model.editDraft(id, draft);
                 }
             }
+        } else {
+            const sub = stream_data.get_sub(stream_name);
+            if (sub !== undefined) {
+                draft.stream_id = sub.stream_id;
+            }
         }
         const draft_topic = draft.topic || compose.empty_topic_placeholder();
-        const draft_stream_color = stream_data.get_color(stream_name);
+        const draft_stream_color = stream_data.get_color(draft.stream_id);
 
         formatted = {
             draft_id: draft.id,
diff --git a/web/src/message_list_view.js b/web/src/message_list_view.js
index f672c64da1..17bb6532c1 100644
--- a/web/src/message_list_view.js
+++ b/web/src/message_list_view.js
@@ -187,7 +187,7 @@ function populate_group_from_message_container(group, message_container) {
     group.is_private = message_container.msg.is_private;
 
     if (group.is_stream) {
-        const color = stream_data.get_color(message_container.msg.stream);
+        const color = stream_data.get_color(message_container.msg.stream_id);
         group.recipient_bar_color = stream_color.get_recipient_bar_color(color);
         group.stream_privacy_icon_color = stream_color.get_stream_privacy_icon_color(color);
         group.invite_only = stream_data.is_invite_only_by_stream_name(message_container.msg.stream);
@@ -409,7 +409,7 @@ export class MessageListView {
         message_container.small_avatar_url = people.small_avatar_url(message_container.msg);
         if (message_container.msg.stream) {
             message_container.background_color = stream_data.get_color(
-                message_container.msg.stream,
+                message_container.msg.stream_id,
             );
         }
 
diff --git a/web/src/narrow_state.js b/web/src/narrow_state.js
index 965077d629..7fe0c16e4a 100644
--- a/web/src/narrow_state.js
+++ b/web/src/narrow_state.js
@@ -93,7 +93,7 @@ export function set_compose_defaults() {
         // So we look up the resolved stream and return that if appropriate.
         const sub = stream_sub();
         if (sub !== undefined) {
-            opts.stream = sub.name;
+            opts.stream_id = sub.stream_id;
         }
     }
 
diff --git a/web/src/pill_typeahead.js b/web/src/pill_typeahead.js
index a4b72265c5..dfac88454d 100644
--- a/web/src/pill_typeahead.js
+++ b/web/src/pill_typeahead.js
@@ -112,7 +112,7 @@ export function set_up($input, pills, opts) {
             return typeahead_helper.sort_recipients({
                 users,
                 query,
-                current_stream: "",
+                current_stream_id: "",
                 current_topic: undefined,
                 groups,
                 max_num_items: undefined,
diff --git a/web/src/scheduled_messages_overlay_ui.js b/web/src/scheduled_messages_overlay_ui.js
index d798dd4af6..930d22e0b9 100644
--- a/web/src/scheduled_messages_overlay_ui.js
+++ b/web/src/scheduled_messages_overlay_ui.js
@@ -70,7 +70,7 @@ function format(scheduled_messages) {
             msg_render_context.stream_name = sub_store.maybe_get_stream_name(
                 msg_render_context.stream_id,
             );
-            const color = stream_data.get_color(msg_render_context.stream_name);
+            const color = stream_data.get_color(msg_render_context.stream_id);
             msg_render_context.recipient_bar_color = stream_color.get_recipient_bar_color(color);
             msg_render_context.stream_privacy_icon_color =
                 stream_color.get_stream_privacy_icon_color(color);
diff --git a/web/src/stream_bar.js b/web/src/stream_bar.js
index 92d747970e..5d438a7d9a 100644
--- a/web/src/stream_bar.js
+++ b/web/src/stream_bar.js
@@ -4,10 +4,10 @@ import * as stream_data from "./stream_data";
 // color look like the stream being used.
 // (In particular, if there's a color associated with it,
 //  have that color be reflected here too.)
-export function decorate(stream_name, $element) {
-    if (stream_name === undefined) {
+export function decorate(stream_id, $element) {
+    if (stream_id === undefined) {
         return;
     }
-    const color = stream_data.get_color(stream_name);
+    const color = stream_data.get_color(stream_id);
     $element.css("background-color", color);
 }
diff --git a/web/src/stream_color.js b/web/src/stream_color.js
index 5ea43c713f..1376348064 100644
--- a/web/src/stream_color.js
+++ b/web/src/stream_color.js
@@ -11,18 +11,16 @@ import * as row from "./rows";
 import * as settings_data from "./settings_data";
 import * as stream_data from "./stream_data";
 import * as stream_settings_ui from "./stream_settings_ui";
-import * as sub_store from "./sub_store";
 
 extend([lchPlugin, mixPlugin]);
 
 export function update_stream_recipient_color($stream_header) {
     if ($stream_header.length) {
         const stream_id = Number.parseInt($($stream_header).attr("data-stream-id"), 10);
-        const stream_name = sub_store.maybe_get_stream_name(stream_id);
-        if (!stream_name) {
+        if (!stream_id) {
             return;
         }
-        const stream_color = stream_data.get_color(stream_name);
+        const stream_color = stream_data.get_color(stream_id);
         const recipient_bar_color = get_recipient_bar_color(stream_color);
         $stream_header
             .find(".message-header-contents")
diff --git a/web/src/stream_data.js b/web/src/stream_data.js
index 300ed1f1a9..4cecd2ae7f 100644
--- a/web/src/stream_data.js
+++ b/web/src/stream_data.js
@@ -453,8 +453,8 @@ export function canonicalized_name(stream_name) {
     return stream_name.toString().toLowerCase();
 }
 
-export function get_color(stream_name) {
-    const sub = get_sub(stream_name);
+export function get_color(stream_id) {
+    const sub = get_sub_by_id(stream_id);
     if (sub === undefined) {
         return DEFAULT_COLOR;
     }
diff --git a/web/src/stream_edit.js b/web/src/stream_edit.js
index aa54f786c1..1556bd3f6c 100644
--- a/web/src/stream_edit.js
+++ b/web/src/stream_edit.js
@@ -135,7 +135,7 @@ function show_subscription_settings(sub) {
     const $edit_container = stream_settings_containers.get_edit_container(sub);
 
     const $colorpicker = $edit_container.find(".colorpicker");
-    const color = stream_data.get_color(sub.name);
+    const color = stream_data.get_color(sub.stream_id);
     stream_color.set_colorpicker_color($colorpicker, color);
     stream_ui_updates.update_add_subscriptions_elements(sub);
 
diff --git a/web/src/stream_popover.js b/web/src/stream_popover.js
index beb5f47089..a72935e1dc 100644
--- a/web/src/stream_popover.js
+++ b/web/src/stream_popover.js
@@ -334,11 +334,9 @@ export function build_move_topic_to_stream_popover(
     }
 
     function render_selected_stream() {
-        const stream_name = sub_store.maybe_get_stream_name(
-            Number.parseInt(stream_widget_value, 10),
-        );
-        stream_bar.decorate(stream_name, $stream_header_colorblock);
-        const stream = stream_data.get_sub_by_name(stream_name);
+        const stream_id = Number.parseInt(stream_widget_value, 10);
+        stream_bar.decorate(stream_id, $stream_header_colorblock);
+        const stream = stream_data.get_sub_by_id(stream_id);
         if (stream === undefined) {
             $("#move_topic_to_stream_widget .dropdown_widget_value").text(
                 $t({defaultMessage: "Select a stream"}),
diff --git a/web/src/stream_settings_ui.js b/web/src/stream_settings_ui.js
index 724a9bf032..5df73605d5 100644
--- a/web/src/stream_settings_ui.js
+++ b/web/src/stream_settings_ui.js
@@ -13,6 +13,7 @@ import * as blueslip from "./blueslip";
 import * as browser_history from "./browser_history";
 import * as channel from "./channel";
 import * as components from "./components";
+import * as compose_recipient from "./compose_recipient";
 import * as compose_state from "./compose_state";
 import * as confirm_dialog from "./confirm_dialog";
 import * as dropdown_widget from "./dropdown_widget";
@@ -167,8 +168,6 @@ export function is_subscribed_stream_tab_active() {
 }
 
 export function update_stream_name(sub, new_name) {
-    const old_name = sub.name;
-
     // Rename the stream internally.
     stream_data.rename_sub(sub, new_name);
     const stream_id = sub.stream_id;
@@ -186,9 +185,9 @@ export function update_stream_name(sub, new_name) {
     // Update the message feed.
     message_live_update.update_stream_name(stream_id, new_name);
 
-    // Update compose_state if needed
-    if (compose_state.stream_name() === old_name) {
-        compose_state.set_stream_name(new_name);
+    // Update compose UI if needed
+    if (compose_state.stream_id() === stream_id) {
+        compose_recipient.on_compose_select_recipient_update();
     }
 
     // Update navbar if needed
diff --git a/web/src/typeahead_helper.js b/web/src/typeahead_helper.js
index a3282fa46b..80f170c1b0 100644
--- a/web/src/typeahead_helper.js
+++ b/web/src/typeahead_helper.js
@@ -233,26 +233,29 @@ export function compare_people_for_relevance(
     return tertiary_compare(person_a, person_b);
 }
 
-export function sort_people_for_relevance(objs, current_stream_name, current_topic) {
+export function sort_people_for_relevance(objs, current_stream_id, current_topic) {
     // If sorting for recipientbox typeahead and not viewing a stream / topic, then current_stream = ""
-    let current_stream = false;
-    if (current_stream_name) {
-        current_stream = stream_data.get_sub(current_stream_name);
+    let current_stream = null;
+    if (current_stream_id) {
+        current_stream = stream_data.get_sub_by_id(current_stream_id);
     }
     if (!current_stream) {
         objs.sort((person_a, person_b) =>
             compare_people_for_relevance(person_a, person_b, compare_by_pms),
         );
     } else {
-        const stream_id = current_stream.stream_id;
-
         objs.sort((person_a, person_b) =>
             compare_people_for_relevance(
                 person_a,
                 person_b,
                 (user_a, user_b) =>
-                    recent_senders.compare_by_recency(user_a, user_b, stream_id, current_topic),
-                current_stream.stream_id,
+                    recent_senders.compare_by_recency(
+                        user_a,
+                        user_b,
+                        current_stream_id,
+                        current_topic,
+                    ),
+                current_stream_id,
             ),
         );
     }
@@ -348,13 +351,13 @@ export function sort_languages(matches, query) {
 export function sort_recipients({
     users,
     query,
-    current_stream,
+    current_stream_id,
     current_topic,
     groups = [],
     max_num_items = 20,
 }) {
     function sort_relevance(items) {
-        return sort_people_for_relevance(items, current_stream, current_topic);
+        return sort_people_for_relevance(items, current_stream_id, current_topic);
     }
 
     const users_name_results = typeahead.triage(query, users, (p) => p.full_name);
diff --git a/web/tests/compose.test.js b/web/tests/compose.test.js
index 5606bf7e5a..678a2bad52 100644
--- a/web/tests/compose.test.js
+++ b/web/tests/compose.test.js
@@ -9,7 +9,6 @@ const {mock_banners} = require("./lib/compose_banner");
 const {$t} = require("./lib/i18n");
 const {mock_esm, set_global, zrequire} = require("./lib/namespace");
 const {run_test} = require("./lib/test");
-const blueslip = require("./lib/zblueslip");
 const $ = require("./lib/zjquery");
 const {page_params, user_settings} = require("./lib/zpage_params");
 
@@ -318,7 +317,7 @@ test_ui("enter_with_preview_open", ({override, override_rewire}) => {
 
     // Test sending a message with content.
     compose_state.set_message_type("stream");
-    compose_state.set_stream_name("social");
+    compose_state.set_stream_id(social.stream_id);
 
     $("#compose-textarea").val("message me");
     $("#compose-textarea").hide();
@@ -727,7 +726,7 @@ test_ui("create_message_object", ({override, override_rewire}) => {
     mock_banners();
     override_rewire(compose_recipient, "on_compose_select_recipient_update", noop);
 
-    compose_state.set_stream_name("social");
+    compose_state.set_stream_id(social.stream_id);
     $("#stream_message_recipient_topic").val("lunch");
     $("#compose-textarea").val("burrito");
 
diff --git a/web/tests/compose_actions.test.js b/web/tests/compose_actions.test.js
index 78bf3df313..8e0f19de93 100644
--- a/web/tests/compose_actions.test.js
+++ b/web/tests/compose_actions.test.js
@@ -127,7 +127,7 @@ test("start", ({override, override_rewire, mock_template}) => {
 
     // Start stream message
     compose_defaults = {
-        stream: "",
+        stream_id: "",
         topic: "topic1",
     };
 
@@ -177,7 +177,7 @@ test("start", ({override, override_rewire, mock_template}) => {
     };
     stream_data.add_sub(social);
 
-    compose_state.set_stream_name("");
+    compose_state.set_stream_id("");
     // More than 1 subscription, do not autofill
     opts = {};
     start("stream", opts);
@@ -270,12 +270,6 @@ test("respond_to_message", ({override, override_rewire, mock_template}) => {
     assert.equal(compose_state.private_message_recipient(), "alice@example.com");
 
     // Test stream
-    msg = {
-        type: "stream",
-        stream: "Denmark",
-        topic: "python",
-    };
-
     const denmark = {
         subscribed: true,
         color: "blue",
@@ -283,6 +277,14 @@ test("respond_to_message", ({override, override_rewire, mock_template}) => {
         stream_id: 1,
     };
     stream_data.add_sub(denmark);
+
+    msg = {
+        type: "stream",
+        stream: denmark.name,
+        stream_id: denmark.stream_id,
+        topic: "python",
+    };
+
     opts = {};
 
     respond_to_message(opts);
@@ -310,7 +312,8 @@ test("reply_with_mention", ({override, override_rewire, mock_template}) => {
 
     const msg = {
         type: "stream",
-        stream: "Denmark",
+        stream: denmark.name,
+        stream_id: denmark.stream_id,
         topic: "python",
         sender_full_name: "Bob Roberts",
         sender_id: 40,
diff --git a/web/tests/compose_fade.test.js b/web/tests/compose_fade.test.js
index 638d50f9b1..b494386d7b 100644
--- a/web/tests/compose_fade.test.js
+++ b/web/tests/compose_fade.test.js
@@ -71,7 +71,7 @@ run_test("set_focused_recipient", ({override_rewire}) => {
     assert.equal(compose_fade_helper.would_receive_message(bob.user_id), true);
 
     stream_data.add_sub(sub);
-    compose_state.set_stream_name("social");
+    compose_state.set_stream_id(sub.stream_id);
     peer_data.set_subscribers(sub.stream_id, [me.user_id, alice.user_id]);
     compose_fade.set_focused_recipient("stream");
 
diff --git a/web/tests/compose_state.test.js b/web/tests/compose_state.test.js
index b53507a118..84d8c0c82f 100644
--- a/web/tests/compose_state.test.js
+++ b/web/tests/compose_state.test.js
@@ -41,7 +41,7 @@ run_test("has_full_recipient", ({override, override_rewire}) => {
     override(compose_pm_pill, "get_emails", () => emails);
 
     compose_state.set_message_type("stream");
-    compose_state.set_stream_name("");
+    compose_state.set_stream_id("");
     compose_state.topic("");
     assert.equal(compose_state.has_full_recipient(), false);
 
@@ -49,7 +49,7 @@ run_test("has_full_recipient", ({override, override_rewire}) => {
     assert.equal(compose_state.has_full_recipient(), false);
 
     stream_data.add_sub({name: "bar", stream_id: 99});
-    compose_state.set_stream_name("bar");
+    compose_state.set_stream_id(99);
     assert.equal(compose_state.has_full_recipient(), true);
 
     compose_state.set_message_type("private");
diff --git a/web/tests/compose_ui.test.js b/web/tests/compose_ui.test.js
index 127f16af36..559d0c7bc8 100644
--- a/web/tests/compose_ui.test.js
+++ b/web/tests/compose_ui.test.js
@@ -20,6 +20,7 @@ mock_esm("../src/message_lists", {
 });
 
 const compose_ui = zrequire("compose_ui");
+const stream_data = zrequire("stream_data");
 const people = zrequire("people");
 const user_status = zrequire("user_status");
 const hash_util = mock_esm("../src/hash_util");
@@ -184,7 +185,7 @@ run_test("replace_syntax", ({override}) => {
 run_test("compute_placeholder_text", () => {
     let opts = {
         message_type: "stream",
-        stream: "",
+        stream_id: "",
         topic: "",
         private_message_recipient: "",
     };
@@ -195,7 +196,13 @@ run_test("compute_placeholder_text", () => {
         $t({defaultMessage: "Compose your message here"}),
     );
 
-    opts.stream = "all";
+    const stream_all = {
+        subscribed: true,
+        name: "all",
+        stream_id: 2,
+    };
+    stream_data.add_sub(stream_all);
+    opts.stream_id = stream_all.stream_id;
     assert.equal(compose_ui.compute_placeholder_text(opts), $t({defaultMessage: "Message #all"}));
 
     opts.topic = "Test";
@@ -207,7 +214,7 @@ run_test("compute_placeholder_text", () => {
     // direct message narrows
     opts = {
         message_type: "private",
-        stream: "",
+        stream_id: "",
         topic: "",
         private_message_recipient: "",
     };
@@ -748,10 +755,20 @@ run_test("get_focus_area", () => {
         "#compose-textarea",
     );
     assert.equal(get_focus_area("stream", {}), "#compose_select_recipient_widget_wrapper");
-    assert.equal(get_focus_area("stream", {stream: "fun"}), "#stream_message_recipient_topic");
-    assert.equal(get_focus_area("stream", {stream: "fun", topic: "more"}), "#compose-textarea");
     assert.equal(
-        get_focus_area("stream", {stream: "fun", topic: "more", trigger: "new topic button"}),
+        get_focus_area("stream", {stream_name: "fun", stream_id: 4}),
+        "#stream_message_recipient_topic",
+    );
+    assert.equal(
+        get_focus_area("stream", {stream_name: "fun", stream_id: 4, topic: "more"}),
+        "#compose-textarea",
+    );
+    assert.equal(
+        get_focus_area("stream", {
+            stream_id: 4,
+            topic: "more",
+            trigger: "new topic button",
+        }),
         "#stream_message_recipient_topic",
     );
 });
diff --git a/web/tests/compose_validate.test.js b/web/tests/compose_validate.test.js
index 7288064994..06161c66d8 100644
--- a/web/tests/compose_validate.test.js
+++ b/web/tests/compose_validate.test.js
@@ -42,6 +42,13 @@ const bob = {
     full_name: "Bob",
 };
 
+const social_sub = {
+    stream_id: 101,
+    name: "social",
+    subscribed: true,
+};
+stream_data.add_sub(social_sub);
+
 people.add_active_user(me);
 people.initialize_current_user(me.user_id);
 
@@ -77,16 +84,17 @@ function stub_message_row($textarea) {
 
 test_ui("validate_stream_message_address_info", ({mock_template}) => {
     mock_banners();
-    const sub = {
+
+    const party_sub = {
         stream_id: 101,
-        name: "social",
+        name: "party",
         subscribed: true,
     };
-    stream_data.add_sub(sub);
+    stream_data.add_sub(party_sub);
     assert.ok(compose_validate.validate_stream_message_address_info("social"));
 
-    sub.subscribed = false;
-    stream_data.add_sub(sub);
+    party_sub.subscribed = false;
+    stream_data.add_sub(party_sub);
     $("#compose_banners .user_not_subscribed").length = 0;
     let user_not_subscribed_rendered = false;
     mock_template("compose_banner/compose_banner.hbs", true, (data, html) => {
@@ -105,9 +113,9 @@ test_ui("validate_stream_message_address_info", ({mock_template}) => {
     };
     assert.ok(compose_validate.validate_stream_message_address_info("social"));
 
-    sub.name = "Frontend";
-    sub.stream_id = 102;
-    stream_data.add_sub(sub);
+    party_sub.name = "Frontend";
+    party_sub.stream_id = 102;
+    stream_data.add_sub(party_sub);
     channel.post = (payload) => {
         assert.equal(payload.data.stream, "Frontend");
         payload.data.subscribed = false;
@@ -262,7 +270,7 @@ test_ui("validate", ({override_rewire, mock_template}) => {
 
     // test validating stream messages
     compose_state.set_message_type("stream");
-    compose_state.set_stream_name("");
+    compose_state.set_stream_id("");
     let empty_stream_error_rendered = false;
     mock_template("compose_banner/compose_banner.hbs", false, (data) => {
         assert.equal(data.classname, compose_banner.CLASSNAMES.missing_stream);
@@ -277,7 +285,7 @@ test_ui("validate", ({override_rewire, mock_template}) => {
         name: "Denmark",
     };
     stream_data.add_sub(denmark);
-    compose_state.set_stream_name("Denmark");
+    compose_state.set_stream_id(denmark.stream_id);
     page_params.realm_mandatory_topics = true;
     compose_state.topic("");
     let missing_topic_error_rendered = false;
@@ -379,13 +387,15 @@ test_ui("validate_stream_message", ({override_rewire, mock_template}) => {
     override_rewire(compose_recipient, "on_compose_select_recipient_update", () => {});
     page_params.user_id = me.user_id;
     page_params.realm_mandatory_topics = false;
-    const sub = {
+
+    const special_sub = {
         stream_id: 101,
-        name: "social",
+        name: "special",
         subscribed: true,
     };
-    stream_data.add_sub(sub);
-    compose_state.set_stream_name("social");
+    stream_data.add_sub(special_sub);
+
+    compose_state.set_stream_id(special_sub.stream_id);
     assert.ok(compose_validate.validate());
     assert.ok(!$("#compose-all-everyone").visible());
 
@@ -433,16 +443,16 @@ test_ui(
         mock_banners();
         override_rewire(compose_recipient, "on_compose_select_recipient_update", () => {});
         page_params.is_admin = false;
-        const sub = {
+        const sub_stream_102 = {
             stream_id: 102,
             name: "stream102",
             subscribed: true,
             stream_post_policy: stream_data.stream_post_policy_values.admins.code,
         };
 
-        stream_data.add_sub(sub);
+        stream_data.add_sub(sub_stream_102);
         compose_state.topic("topic102");
-        compose_state.set_stream_name("stream102");
+        compose_state.set_stream_id(sub_stream_102.stream_id);
 
         let banner_rendered = false;
         mock_template("compose_banner/compose_banner.hbs", false, (data) => {
@@ -459,13 +469,13 @@ test_ui(
         assert.ok(banner_rendered);
 
         // Reset error message.
-        compose_state.set_stream_name("social");
+        compose_state.set_stream_id(social_sub.stream_id);
 
         page_params.is_admin = false;
         page_params.is_guest = true;
 
         compose_state.topic("topic102");
-        compose_state.set_stream_name("stream102");
+        compose_state.set_stream_id(sub_stream_102.stream_id);
         banner_rendered = false;
         assert.ok(!compose_validate.validate());
         assert.ok(banner_rendered);
@@ -491,7 +501,7 @@ test_ui(
 
         stream_data.add_sub(sub);
         compose_state.topic("topic104");
-        compose_state.set_stream_name("stream104");
+        compose_state.set_stream_id(sub.stream_id);
         let banner_rendered = false;
         mock_template("compose_banner/compose_banner.hbs", false, (data) => {
             assert.equal(data.classname, compose_banner.CLASSNAMES.no_post_permissions);
@@ -506,7 +516,7 @@ test_ui(
         assert.ok(!compose_validate.validate());
         assert.ok(banner_rendered);
         // Reset error message.
-        compose_state.set_stream_name("social");
+        compose_state.set_stream_id(social_sub.stream_id);
 
         page_params.is_guest = true;
         assert.ok(!compose_validate.validate());
@@ -530,7 +540,7 @@ test_ui(
 
         stream_data.add_sub(sub);
         compose_state.topic("topic103");
-        compose_state.set_stream_name("stream103");
+        compose_state.set_stream_id(sub.stream_id);
         let banner_rendered = false;
         mock_template("compose_banner/compose_banner.hbs", false, (data) => {
             assert.equal(data.classname, compose_banner.CLASSNAMES.no_post_permissions);
@@ -692,7 +702,7 @@ test_ui("warn_if_mentioning_unsubscribed_user", ({override, override_rewire, moc
     override_rewire(compose_recipient, "on_compose_select_recipient_update", () => {});
     const $textarea = $("<textarea>").attr("id", "compose-textarea");
     stub_message_row($textarea);
-    compose_state.set_stream_name("");
+    compose_state.set_stream_id("");
     override(settings_data, "user_can_subscribe_other_users", () => true);
 
     let mentioned_details = {
@@ -737,7 +747,7 @@ test_ui("warn_if_mentioning_unsubscribed_user", ({override, override_rewire, moc
         name: "random",
     };
     stream_data.add_sub(sub);
-    compose_state.set_stream_name("random");
+    compose_state.set_stream_id(sub.stream_id);
 
     // Test with invalid stream in compose box. It should return noop.
     new_banner_rendered = false;
@@ -804,8 +814,7 @@ test_ui("test warn_if_topic_resolved", ({override, override_rewire, mock_templat
     stream_data.add_sub(sub);
 
     compose_state.set_message_type("stream");
-    blueslip.expect("error", "Unable to select stream: Do not exist");
-    compose_state.set_stream_name("Do not exist");
+    compose_state.set_stream_id("");
     compose_state.topic(resolved_topic.resolve_name("hello"));
     compose_state.message_content("content");
 
@@ -813,7 +822,7 @@ test_ui("test warn_if_topic_resolved", ({override, override_rewire, mock_templat
     compose_validate.warn_if_topic_resolved(true);
     assert.ok(!error_shown);
 
-    compose_state.set_stream_name("random");
+    compose_state.set_stream_id(sub.stream_id);
 
     // Show the warning now as stream also exists
     error_shown = false;
diff --git a/web/tests/composebox_typeahead.test.js b/web/tests/composebox_typeahead.test.js
index 350238c953..12ae928633 100644
--- a/web/tests/composebox_typeahead.test.js
+++ b/web/tests/composebox_typeahead.test.js
@@ -744,7 +744,7 @@ test("initialize", ({override, override_rewire, mock_template}) => {
             return sweden_topics_to_show;
         });
 
-        compose_state.set_stream_name("Sweden");
+        compose_state.set_stream_id(sweden_stream.stream_id);
         let actual_value = options.source();
         // Topics should be sorted alphabetically, not by addition order.
         let expected_value = sweden_topics_to_show;
@@ -800,8 +800,8 @@ test("initialize", ({override, override_rewire, mock_template}) => {
 
         topic_typeahead_called = true;
 
-        // Unset the stream name.
-        compose_state.set_stream_name("");
+        // Unset the stream.
+        compose_state.set_stream_id("");
     };
 
     let pm_recipient_typeahead_called = false;
@@ -881,7 +881,7 @@ test("initialize", ({override, override_rewire, mock_template}) => {
             return typeahead_helper.sort_recipients({
                 users: people,
                 query,
-                current_stream: compose_state.stream_name(),
+                current_stream_id: compose_state.stream_id(),
                 current_topic: compose_state.topic(),
             });
         }
@@ -1139,7 +1139,7 @@ test("initialize", ({override, override_rewire, mock_template}) => {
     assert.equal($("#private_message_recipient").val(), "othello@zulip.com");
 
     // the UI of selecting a stream is tested in puppeteer tests.
-    compose_state.set_stream_name("Sweden");
+    compose_state.set_stream_id(sweden_stream.stream_id);
 
     let event = {
         type: "keydown",
@@ -1199,7 +1199,7 @@ test("initialize", ({override, override_rewire, mock_template}) => {
     $("form#send_message_form").trigger(event);
 
     // the UI of selecting a stream is tested in puppeteer tests.
-    compose_state.set_stream_name("Sweden");
+    compose_state.set_stream_id(sweden_stream.stream_id);
     // handle_keyup()
     event = {
         type: "keydown",
@@ -1800,12 +1800,12 @@ test("direct message recipients sorted according to stream / topic being viewed"
     override_rewire(compose_recipient, "on_compose_select_recipient_update", () => {});
 
     // When viewing no stream, sorting is alphabetical
-    compose_state.set_stream_name("");
+    compose_state.set_stream_id("");
     results = ct.get_pm_people("li");
     assert.deepEqual(results, [ali, alice, cordelia]);
 
     // When viewing denmark stream, subscriber cordelia is placed higher
-    compose_state.set_stream_name("Denmark");
+    compose_state.set_stream_id(denmark_stream.stream_id);
     results = ct.get_pm_people("li");
     assert.deepEqual(results, [cordelia, ali, alice]);
 
diff --git a/web/tests/dispatch_subs.test.js b/web/tests/dispatch_subs.test.js
index d05b50768f..b155ea96bb 100644
--- a/web/tests/dispatch_subs.test.js
+++ b/web/tests/dispatch_subs.test.js
@@ -275,7 +275,7 @@ test("stream delete (stream is selected in compose)", ({override, override_rewir
     }
 
     stream_data.subscribe_myself(event.streams[0]);
-    compose_state.set_stream_name(event.streams[0].name);
+    compose_state.set_stream_id(event.streams[0].stream_id);
 
     override(settings_streams, "update_default_streams_table", noop);
 
diff --git a/web/tests/drafts.test.js b/web/tests/drafts.test.js
index 2ac696a039..c832a7e9af 100644
--- a/web/tests/drafts.test.js
+++ b/web/tests/drafts.test.js
@@ -81,6 +81,7 @@ const draft_2 = {
 };
 const short_msg = {
     stream: "stream",
+    stream_id: 30,
     topic: "topic",
     type: "stream",
     content: "a",
@@ -159,11 +160,6 @@ test("snapshot_message", ({override_rewire}) => {
     override_rewire(compose_recipient, "on_compose_select_recipient_update", () => {});
     mock_banners();
 
-    override_rewire(stream_data, "get_sub", (stream_name) => {
-        assert.equal(stream_name, "stream");
-        return {stream_id: 30};
-    });
-
     $(".narrow_to_compose_recipients").toggleClass = noop;
 
     mock_stream_header_colorblock();
@@ -176,7 +172,7 @@ test("snapshot_message", ({override_rewire}) => {
         if (curr_draft.type === "private") {
             compose_state.set_compose_recipient_id(compose_recipient.DIRECT_MESSAGE_ID);
         } else {
-            compose_state.set_stream_name(curr_draft.stream);
+            compose_state.set_stream_id(curr_draft.stream_id);
         }
         compose_state.topic(curr_draft.topic);
         compose_state.private_message_recipient(curr_draft.private_message_recipient);
@@ -187,7 +183,7 @@ test("snapshot_message", ({override_rewire}) => {
         name: draft_1.stream,
     };
     stream_data.add_sub(stream);
-    compose_state.set_stream_name("stream");
+    compose_state.set_stream_id(stream.stream_id);
 
     curr_draft = draft_1;
     set_compose_state();
diff --git a/web/tests/narrow.test.js b/web/tests/narrow.test.js
index ea9bf811d1..9490a6b00f 100644
--- a/web/tests/narrow.test.js
+++ b/web/tests/narrow.test.js
@@ -662,7 +662,7 @@ run_test("narrow_to_compose_target errors", ({override_rewire, disallow_rewire})
 
     // No-op when empty stream.
     compose_state.set_message_type("stream");
-    compose_state.set_stream_name("");
+    compose_state.set_stream_id("");
     narrow.to_compose_target();
 });
 
@@ -677,7 +677,7 @@ run_test("narrow_to_compose_target streams", ({override_rewire}) => {
 
     compose_state.set_message_type("stream");
     stream_data.add_sub({name: "ROME", stream_id: 99});
-    compose_state.set_stream_name("ROME");
+    compose_state.set_stream_id(99);
 
     // Test with existing topic
     compose_state.topic("one");
diff --git a/web/tests/narrow_state.test.js b/web/tests/narrow_state.test.js
index 73de4ea50c..b5950b2501 100644
--- a/web/tests/narrow_state.test.js
+++ b/web/tests/narrow_state.test.js
@@ -176,13 +176,13 @@ test("set_compose_defaults", () => {
 
     // First try with a stream that doesn't exist.
     let stream_and_topic = narrow_state.set_compose_defaults();
-    assert.equal(stream_and_topic.stream, undefined);
+    assert.equal(stream_and_topic.stream_id, undefined);
     assert.equal(stream_and_topic.topic, "Bar");
 
     const test_stream = {name: "Foo", stream_id: 72};
     stream_data.add_sub(test_stream);
     stream_and_topic = narrow_state.set_compose_defaults();
-    assert.equal(stream_and_topic.stream, "Foo");
+    assert.equal(stream_and_topic.stream_id, 72);
     assert.equal(stream_and_topic.topic, "Bar");
 
     set_filter([["dm", "foo@bar.com"]]);
@@ -217,7 +217,7 @@ test("set_compose_defaults", () => {
     set_filter([["stream", "rome"]]);
 
     const stream_test = narrow_state.set_compose_defaults();
-    assert.equal(stream_test.stream, "ROME");
+    assert.equal(stream_test.stream_id, 99);
 });
 
 test("update_email", () => {
diff --git a/web/tests/stream_data.test.js b/web/tests/stream_data.test.js
index a290457874..7b7ad4b869 100644
--- a/web/tests/stream_data.test.js
+++ b/web/tests/stream_data.test.js
@@ -136,8 +136,8 @@ test("basics", () => {
     assert.ok(stream_data.is_invite_only_by_stream_name("social"));
     assert.ok(!stream_data.is_invite_only_by_stream_name("unknown"));
 
-    assert.equal(stream_data.get_color("social"), "red");
-    assert.equal(stream_data.get_color("unknown"), "#c2c2c2");
+    assert.equal(stream_data.get_color(social.stream_id), "red");
+    assert.equal(stream_data.get_color(""), "#c2c2c2");
 
     assert.equal(stream_data.get_name("denMARK"), "Denmark");
     assert.equal(stream_data.get_name("unknown Stream"), "unknown Stream");
diff --git a/web/tests/typeahead_helper.test.js b/web/tests/typeahead_helper.test.js
index f74665723b..be5d7ecd36 100644
--- a/web/tests/typeahead_helper.test.js
+++ b/web/tests/typeahead_helper.test.js
@@ -95,10 +95,20 @@ for (const person of matches) {
     people.add_active_user(person);
 }
 
-stream_data.create_streams([
-    {name: "Dev", color: "blue", stream_id: 1},
-    {name: "Linux", color: "red", stream_id: 2},
-]);
+const dev_sub = {
+    name: "Dev",
+    color: "blue",
+    stream_id: 1,
+};
+
+const linux_sub = {
+    name: "Linux",
+    color: "red",
+    stream_id: 2,
+};
+stream_data.create_streams([dev_sub, linux_sub]);
+stream_data.add_sub(dev_sub);
+stream_data.add_sub(linux_sub);
 
 function test(label, f) {
     run_test(label, (helpers) => {
@@ -312,11 +322,11 @@ test("sort_languages", () => {
     assert.deepEqual(test_langs, ["js", "java"]);
 });
 
-function get_typeahead_result(query, current_stream, current_topic) {
+function get_typeahead_result(query, current_stream_id, current_topic) {
     const result = th.sort_recipients({
         users: people.get_realm_users(),
         query,
-        current_stream,
+        current_stream_id,
         current_topic,
     });
     return result.map((person) => person.email);
@@ -378,8 +388,8 @@ test("sort_recipients", () => {
         id: (next_id += 1),
     });
 
-    // Typeahead for stream message [query, stream-name, topic-name]
-    assert.deepEqual(get_typeahead_result("b", "Dev", "Dev topic"), [
+    // Typeahead for stream message [query, stream-id, topic-name]
+    assert.deepEqual(get_typeahead_result("b", dev_sub.stream_id, "Dev topic"), [
         subscriber_email_3,
         subscriber_email_2,
         subscriber_email_1,
@@ -403,7 +413,7 @@ test("sort_recipients", () => {
     });
 
     // No match
-    assert.deepEqual(get_typeahead_result("h", "Linux", "Linux topic"), [
+    assert.deepEqual(get_typeahead_result("h", linux_sub.stream_id, "Linux topic"), [
         "zman@test.net",
         "b_user_3@zulip.net",
         "a_user@zulip.org",
@@ -427,7 +437,7 @@ test("sort_recipients all mention", () => {
     const results = th.sort_recipients({
         users: test_objs,
         query: "a",
-        current_stream: "Linux",
+        current_stream_id: linux_sub.stream_id,
         current_topic: "Linux topic",
     });
 
@@ -454,10 +464,9 @@ test("sort_recipients pm counts", () => {
     ]);
 
     // Now prioritize stream membership over pm counts.
-    const linux_sub = stream_data.get_sub("Linux");
     peer_data.add_subscriber(linux_sub.stream_id, b_user_3.user_id);
 
-    assert.deepEqual(get_typeahead_result("b", "Linux", "Linux topic"), [
+    assert.deepEqual(get_typeahead_result("b", linux_sub.stream_id, "Linux topic"), [
         "b_user_3@zulip.net",
         "b_user_1@zulip.net",
         "b_user_2@zulip.net",
@@ -489,7 +498,7 @@ test("sort_recipients dup bots", () => {
     const recipients = th.sort_recipients({
         users: dup_objects,
         query: "b",
-        current_stream: "",
+        current_stream_id: "",
         current_topic: "",
     });
     const recipients_email = recipients.map((person) => person.email);
@@ -516,7 +525,7 @@ test("sort_recipients dup alls", () => {
     const recipients = th.sort_recipients({
         users: test_objs,
         query: "a",
-        current_stream: "Linux",
+        current_stream_id: linux_sub.stream_id,
         current_topic: "Linux topic",
     });
 
@@ -546,7 +555,7 @@ test("sort_recipients subscribers", () => {
     const recipients = th.sort_recipients({
         users: small_matches,
         query: "b",
-        current_stream: "Dev",
+        current_stream_id: dev_sub.stream_id,
         current_topic: "Dev topic",
     });
     const recipients_email = recipients.map((person) => person.email);
@@ -561,7 +570,7 @@ test("sort_recipients pm partners", () => {
     const recipients = th.sort_recipients({
         users: small_matches,
         query: "b",
-        current_stream: "Linux",
+        current_stream_id: linux_sub.stream_id,
         current_topic: "Linux topic",
     });
     const recipients_email = recipients.map((person) => person.email);