diff --git a/extensions/whoami.test.ts b/extensions/whoami.test.ts
index 8b54febfd..984b7697f 100644
--- a/extensions/whoami.test.ts
+++ b/extensions/whoami.test.ts
@@ -48,6 +48,7 @@ beforeAll(async () => {
             create_shortcut: true,
             payment_bypass: true,
         },
+        teams_enabled: true,
     } as never);
 });
 
@@ -66,6 +67,81 @@ const seedUser = async () => {
 };
 
 describe('whoami extension — handleWhoami', () => {
+    // The sidebar label needs this at boot, which is why it rides whoami
+    // rather than a call of its own.
+    describe('the team an account belongs to', () => {
+        // A seat is created, never adopted, so it must have no password.
+        const seedSeat = async () => {
+            const slug = Math.random().toString(36).slice(2, 8);
+            return server.stores.user.create({
+                username: `wseat_${slug}`,
+                uuid: uuidv4(),
+                password: null,
+                email: null,
+            });
+        };
+
+        const seatOf = async (teamName: string) => {
+            const owner = await seedUser();
+            const seat = await seedSeat();
+            const team = await server.stores.team.create({
+                ownerUserId: owner.id as number,
+                name: teamName,
+                handle: `wt-${Math.random().toString(36).slice(2, 9)}`,
+            });
+            await server.stores.team.addMember(team.uid, seat.id as number, {
+                orgOwned: true,
+            });
+            return { seat, team };
+        };
+
+        it('names the team for a seat', async () => {
+            const { seat, team } = await seatOf('Acme Corp');
+            const { res, captured } = makeRes();
+
+            await runWithContext(
+                { actor: { user: { uuid: seat.uuid, id: seat.id as number } } },
+                () => handleWhoami(makeReq(), res),
+            );
+
+            expect((captured.body as { team?: unknown }).team).toEqual({
+                uid: team.uid,
+                name: 'Acme Corp',
+            });
+        });
+
+        it('says nothing for an account that is not a seat', async () => {
+            const user = await seedUser();
+            const { res, captured } = makeRes();
+
+            await runWithContext(
+                { actor: { user: { uuid: user.uuid, id: user.id as number } } },
+                () => handleWhoami(makeReq(), res),
+            );
+
+            expect(captured.body).not.toHaveProperty('team');
+        });
+
+        it('withholds it from an app actor', async () => {
+            // Same class as the phone number: a seat's employer is not an
+            // app's business.
+            const { seat } = await seatOf('Acme Corp');
+            const { res, captured } = makeRes();
+
+            await runWithContext(
+                {
+                    actor: {
+                        user: { uuid: seat.uuid, id: seat.id as number },
+                        app: { uid: 'app-1' },
+                    },
+                },
+                () => handleWhoami(makeReq(), res),
+            );
+
+            expect(captured.body).not.toHaveProperty('team');
+        });
+    });
+
     it('returns 401 when no actor is on the context', async () => {
         const { res, captured } = makeRes();
 
diff --git a/extensions/whoami.ts b/extensions/whoami.ts
index 049788b7d..57ba963e9 100644
--- a/extensions/whoami.ts
+++ b/extensions/whoami.ts
@@ -253,6 +253,23 @@ export const handleWhoami = async (
         details.directories = directories;
     }
 
+    // The team an account belongs to, when it is one a team pays for. User
+    // actors only, and only where teams are on.
+    if (isUser && extension.config.teams_enabled === true) {
+        try {
+            const seat = await stores.team.getOrgSeat(user.id);
+            if (seat) {
+                details.team = {
+                    uid: seat.team_uid,
+                    name: seat.team_name ?? null,
+                };
+            }
+        } catch (e) {
+            // Never fail whoami over this; the account still works without it.
+            console.warn('[whoami] team lookup failed:', (e as Error).message);
+        }
+    }
+
     // Last activity
     const lastActivityTs = toUnixSeconds(user.last_activity_ts);
     if (lastActivityTs !== undefined) {
diff --git a/src/backend/stores/team/TeamStore.ts b/src/backend/stores/team/TeamStore.ts
index 661ff2550..de4ee28b4 100644
--- a/src/backend/stores/team/TeamStore.ts
+++ b/src/backend/stores/team/TeamStore.ts
@@ -53,6 +53,7 @@ export interface OrgSeatRow {
     uuid: string;
     username: string;
     team_uid: string;
+    team_name: string | null;
     owner_user_id: number;
 }
 
@@ -626,7 +627,8 @@ export class TeamStore extends PuterStore {
     async #readOrgSeat(userId: number): Promise<OrgSeatRow | null> {
         const rows = (await this.clients.db.read(
             'SELECT ug.`id`, ug.`user_id`, u.`uuid`, u.`username`, ' +
-                'g.`uid` AS `team_uid`, g.`owner_user_id` ' +
+                'g.`uid` AS `team_uid`, g.`name` AS `team_name`, ' +
+                'g.`owner_user_id` ' +
                 'FROM `jct_user_group` ug ' +
                 'JOIN `user` u ON u.`id` = ug.`user_id` ' +
                 'JOIN `group` g ON g.`id` = ug.`group_id` ' +
diff --git a/src/gui/src/UI/Dashboard/UIDashboard.js b/src/gui/src/UI/Dashboard/UIDashboard.js
index 559b0d9d2..b00784d23 100644
--- a/src/gui/src/UI/Dashboard/UIDashboard.js
+++ b/src/gui/src/UI/Dashboard/UIDashboard.js
@@ -53,6 +53,7 @@ import TabUsage from './TabUsage.js';
 import TabAccount from './TabAccount.js';
 import TabSecurity from './TabSecurity.js';
 import TabTeams from './TabTeams.js';
+import teamBadgeHtml from './teamBadge.js';
 
 // Registry of built-in tabs
 const builtinTabs = [
@@ -119,7 +120,10 @@ async function UIDashboard (options) {
         h += '<div class="dashboard-sidebar hide-scrollbar">';
             // Sidebar header with logo and collapse toggle
             h += '<div class="dashboard-sidebar-header">';
-                h += `<div class="dashboard-sidebar-logo"><img class="dashboard-sidebar-logo-light" src="${window.icons['logo.svg']}" alt="Puter"><img class="dashboard-sidebar-logo-dark" src="${window.icons['logo-white.svg']}" alt="Puter"><span>Puter</span></div>`;
+                h += '<div class="dashboard-sidebar-brand">';
+                    h += `<div class="dashboard-sidebar-logo"><img class="dashboard-sidebar-logo-light" src="${window.icons['logo.svg']}" alt="Puter"><img class="dashboard-sidebar-logo-dark" src="${window.icons['logo-white.svg']}" alt="Puter"><span>Puter</span></div>`;
+                    h += teamBadgeHtml(window.user);
+                h += '</div>';
                 h += '<button class="dashboard-sidebar-collapse-toggle">';
                     h += `<img class="sidebar-toggle-close" src="${window.icons['sidebar-close.svg']}">`;
                     h += `<img class="sidebar-toggle-open" src="${window.icons['sidebar-open.svg']}">`;
diff --git a/src/gui/src/UI/Dashboard/teamBadge.js b/src/gui/src/UI/Dashboard/teamBadge.js
new file mode 100644
index 000000000..9dce269da
--- /dev/null
+++ b/src/gui/src/UI/Dashboard/teamBadge.js
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2024-present Puter Technologies Inc.
+ *
+ * This file is part of Puter.
+ *
+ * Puter is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * The team name under the sidebar wordmark. Empty for anyone but a seat —
+ * `whoami` sets `team` only for an account a team pays for.
+ *
+ * @param {object} [user] `window.user`
+ * @returns {string} markup, or '' when there is nothing to say
+ */
+export const teamBadgeHtml = (user) => {
+    const name = user?.team?.name;
+    if ( typeof name !== 'string' || name.trim() === '' ) return '';
+    const label = window.html_encode(name);
+    const title = window.html_encode(i18n('teams_account_of', [name]));
+    return `<div class="dashboard-sidebar-team" title="${title}">${label}</div>`;
+};
+
+export default teamBadgeHtml;
diff --git a/src/gui/src/UI/Dashboard/teamBadge.test.js b/src/gui/src/UI/Dashboard/teamBadge.test.js
new file mode 100644
index 000000000..f9069be98
--- /dev/null
+++ b/src/gui/src/UI/Dashboard/teamBadge.test.js
@@ -0,0 +1,36 @@
+import { describe, expect, it } from 'vitest';
+
+globalThis.i18n = (key, args) => `${key}:${(args ?? []).join(',')}`;
+globalThis.window = { html_encode: (v) => String(v).replace(/</g, '&lt;') };
+
+const { teamBadgeHtml } = await import('./teamBadge.js');
+
+describe('the sidebar team badge', () => {
+    it('names the team for a seat', () => {
+        const h = teamBadgeHtml({ team: { uid: 't-1', name: 'Acme Corp' } });
+        expect(h).toContain('dashboard-sidebar-team');
+        expect(h).toContain('Acme Corp');
+    });
+
+    it('says nothing for anyone who is not a seat', () => {
+        // whoami omits `team` entirely for an ordinary account or an owner.
+        for (const user of [undefined, {}, { team: undefined }, { team: {} }]) {
+            expect(teamBadgeHtml(user)).toBe('');
+        }
+    });
+
+    it('treats a blank name as nothing to say', () => {
+        expect(teamBadgeHtml({ team: { uid: 't-1', name: '   ' } })).toBe('');
+    });
+
+    it('encodes the name, which an admin chose', () => {
+        const h = teamBadgeHtml({ team: { name: '<script>x</script>' } });
+        expect(h).not.toContain('<script>');
+        expect(h).toContain('&lt;script');
+    });
+
+    it('explains itself in the title, for a truncated name', () => {
+        const h = teamBadgeHtml({ team: { name: 'Acme' } });
+        expect(h).toContain('teams_account_of:Acme');
+    });
+});
diff --git a/src/gui/src/css/dashboard.css b/src/gui/src/css/dashboard.css
index 725cec118..90afc834d 100644
--- a/src/gui/src/css/dashboard.css
+++ b/src/gui/src/css/dashboard.css
@@ -268,6 +268,22 @@ body {
     margin-bottom: 10px;
 }
 
+.dashboard-sidebar-brand {
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+    min-width: 0;
+}
+
+.dashboard-sidebar-team {
+    font-size: 12px;
+    color: var(--dashboard-text-muted);
+    padding-left: 34px;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
 .dashboard-sidebar-logo {
     display: flex;
     gap: 10px;
@@ -344,7 +360,8 @@ body {
     padding: 4px 0 12px;
 }
 
-.dashboard-sidebar.collapsed .dashboard-sidebar-logo {
+.dashboard-sidebar.collapsed .dashboard-sidebar-logo,
+.dashboard-sidebar.collapsed .dashboard-sidebar-team {
     display: none;
 }
 
diff --git a/src/gui/src/i18n/translations/en.js b/src/gui/src/i18n/translations/en.js
index 82dd6dd3d..dc843001e 100644
--- a/src/gui/src/i18n/translations/en.js
+++ b/src/gui/src/i18n/translations/en.js
@@ -528,6 +528,7 @@ const en = {
         teams_create_team_prompt: 'What should the team be called?',
         teams_accounts: 'Accounts',
         teams_no_accounts: 'This team has no accounts yet.',
+        teams_account_of: 'This account belongs to %%',
         teams_add_account: 'Add an account',
         teams_email_optional: 'Email (optional)',
         teams_add_account_email_hint: 'If you add an address, we email the username and temporary password to it. Otherwise the password below is the only copy.',