diff --git a/apps/hq/src/api.ts b/apps/hq/src/api.ts
index 64117c1..3a001bd 100644
--- a/apps/hq/src/api.ts
+++ b/apps/hq/src/api.ts
@@ -1,4 +1,5 @@
 import { Router, type Request, type RequestHandler, type Response } from 'express'
+import { validateGstin } from '@sims/domain'
 import { login, requireAuth, requireOwner } from './auth'
 import type { DB } from './db'
 import {
@@ -32,7 +33,7 @@ import {
   listInteractionTypes, updateInteraction, type CreateInteractionInput, type InteractionPatch,
 } from './repos-interactions'
 import {
-  dismissReminder, getReminder, listQueue, listReminders,
+  dismissReminder, getReminder, listQueue, listReminders, setSetting,
   type ReminderStatus,
 } from './repos-reminders'
 import { sendReminder, type SendReminderDeps } from './send-reminder'
@@ -529,5 +530,35 @@ export function apiRouter(db: DB, gmailDeps?: Partial<GmailDeps>): Router {
     res.json({ ok: true, rows: clientProfitability(db, rangeOf(req)) })
   })
 
+  // ---------- company profile (owner-editable; PDFs read these live) ----------
+  const COMPANY_FIELDS: Record<string, string> = {
+    name: 'company.name', address: 'company.address', gstin: 'company.gstin',
+    stateCode: 'company.state_code', phone: 'company.phone', email: 'company.email', bank: 'company.bank',
+  }
+  r.get('/settings/company', requireAuth, (_req, res) => {
+    res.json({ ok: true, company: companySettings() })
+  })
+  r.put('/settings/company', requireAuth, requireOwner, (req, res) => {
+    const body = req.body as Record<string, unknown>
+    try {
+      const gstin = body['gstin']
+      if (typeof gstin === 'string' && gstin !== '') {
+        const v = validateGstin(gstin)
+        if (!v.ok) throw new Error(`Invalid GSTIN (${v.reason ?? 'invalid'})`)
+      }
+      const stateCode = body['stateCode']
+      if (typeof stateCode === 'string' && !/^\d{2}$/.test(stateCode)) {
+        throw new Error('State code must be two digits')
+      }
+      for (const [field, key] of Object.entries(COMPANY_FIELDS)) {
+        const val = body[field]
+        if (typeof val === 'string') setSetting(db, staffId(res), key, val)
+      }
+      res.json({ ok: true, company: companySettings() })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
+
   return r
 }
diff --git a/apps/hq/test/settings-company.test.ts b/apps/hq/test/settings-company.test.ts
new file mode 100644
index 0000000..d6b6836
--- /dev/null
+++ b/apps/hq/test/settings-company.test.ts
@@ -0,0 +1,46 @@
+// apps/hq/test/settings-company.test.ts
+import { describe, it, expect, afterAll } from 'vitest'
+import express from 'express'
+import { openDb } from '../src/db'
+import { seedIfEmpty } from '../src/seed'
+import { createStaff } from '../src/auth'
+import { apiRouter } from '../src/api'
+
+function appWith() {
+  const db = openDb(':memory:'); seedIfEmpty(db)
+  createStaff(db, { email: 'owner@test.in', displayName: 'Owner', role: 'owner', password: 'owner-password' })
+  createStaff(db, { email: 'staff@test.in', displayName: 'Staff', role: 'staff', password: 'staff-password' })
+  const app = express(); app.use(express.json()); app.locals['db'] = db; app.use('/api', apiRouter(db))
+  const server = app.listen(0)
+  const base = `http://localhost:${(server.address() as { port: number }).port}/api`
+  return { db, server, base }
+}
+
+describe('company profile settings', () => {
+  const { db, server, base } = appWith()
+  afterAll(() => server.close())
+  const login = async (email: string, password: string) =>
+    (await (await fetch(`${base}/auth/login`, { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify({ email, password }) })).json() as any).token
+  const call = async (token: string, method: string, path: string, body?: unknown) => {
+    const res = await fetch(base + path, { method, headers: { 'content-type': 'application/json', authorization: `Bearer ${token}` }, ...(body ? { body: JSON.stringify(body) } : {}) })
+    return { status: res.status, json: await res.json() as any }
+  }
+
+  it('owner reads and updates company.* and it is audited', async () => {
+    const token = await login('owner@test.in', 'owner-password')
+    const before = await call(token, 'GET', '/settings/company')
+    expect(before.json.company['company.name']).toBe('Tecnostac')
+    const put = await call(token, 'PUT', '/settings/company', { name: 'Tecnostac Pvt Ltd', phone: '0484-1234567', stateCode: '32' })
+    expect(put.status).toBe(200)
+    expect(put.json.company['company.name']).toBe('Tecnostac Pvt Ltd')
+    expect(put.json.company['company.phone']).toBe('0484-1234567')
+    const audits = db.prepare(`SELECT COUNT(*) AS n FROM audit_log WHERE entity='setting' AND entity_id LIKE 'company.%'`).get() as { n: number }
+    expect(audits.n).toBeGreaterThanOrEqual(3)
+  })
+  it('rejects a staff PUT (owner only) and an invalid GSTIN', async () => {
+    const staff = await login('staff@test.in', 'staff-password')
+    expect((await call(staff, 'PUT', '/settings/company', { name: 'Nope' })).status).toBe(403)
+    const owner = await login('owner@test.in', 'owner-password')
+    expect((await call(owner, 'PUT', '/settings/company', { gstin: 'NOTAGSTIN' })).status).toBe(400)
+  })
+})