diff --git a/apps/hq-web/src/api.ts b/apps/hq-web/src/api.ts
index c6bd3f0..c9d3725 100644
--- a/apps/hq-web/src/api.ts
+++ b/apps/hq-web/src/api.ts
@@ -935,6 +935,15 @@ export interface SmsBalances {
 export const getSmsBalances = (): Promise<SmsBalances> =>
   apiFetch<SmsBalances>('/reports/sms-balances')
 
+// D28: operations settings — SMS gateway URL, low-balance threshold, ticket SLA (owner).
+export interface OperationsSettings {
+  smsBalanceApiUrl: string; smsLowThreshold: number; ticketSlaDays: number
+}
+export const getOperationsSettings = (): Promise<OperationsSettings> =>
+  apiFetch<OperationsSettings & { ok: boolean }>('/settings/operations')
+export const putOperationsSettings = (body: Partial<OperationsSettings>): Promise<OperationsSettings> =>
+  apiFetch<OperationsSettings & { ok: boolean }>('/settings/operations', { method: 'PUT', body: JSON.stringify(body) })
+
 // D28: live balance fetch from the gateway (managerial — decrypts credentials).
 export interface SmsRefreshSummary {
   attempted: number; ok: number; failed: number; changed: number; skipped: number
diff --git a/apps/hq-web/src/pages/Settings.tsx b/apps/hq-web/src/pages/Settings.tsx
index 832347c..fb77a04 100644
--- a/apps/hq-web/src/pages/Settings.tsx
+++ b/apps/hq-web/src/pages/Settings.tsx
@@ -2,12 +2,13 @@ import { useEffect, useState } from 'react'
 import { useSearchParams } from 'react-router-dom'
 import { formatINR } from '@sims/domain'
 import {
-  Button, DataTable, Dialog, EmptyState, ErrorState, FormField, FormGrid,
+  Button, DataTable, Dialog, EmptyState, ErrorState, FormField, FormGrid, Toolbar,
   Notice, PageHeader, Skeleton, ThemeSwitcher, useToast,
 } from '@sims/ui'
 import {
   createSchedule, getAwsRanking, getCompanyProfile, getEmailStatus, getReminderSettings,
   getSharingSettings, putCompanyProfile, putReminderSettings, putSharingSettings, role,
+  getOperationsSettings, putOperationsSettings, type OperationsSettings,
 } from '../api'
 import { COMPANY_FIELDS, TemplatePanel } from './DocumentTemplate'
 import { useData } from './Clients'
@@ -15,12 +16,13 @@ import { useData } from './Clients'
 const inr = (p: number) => formatINR(p, { symbol: false })
 
 type Dict = Record<string, string>
-type SectionKey = 'company' | 'template' | 'reminders' | 'sharing' | 'integrations' | 'appearance'
+type SectionKey = 'company' | 'template' | 'reminders' | 'operations' | 'sharing' | 'integrations' | 'appearance'
 
 const SECTIONS: { key: SectionKey; label: string; ownerOnly: boolean }[] = [
   { key: 'company', label: 'Company', ownerOnly: true },
   { key: 'template', label: 'Document template', ownerOnly: true },
   { key: 'reminders', label: 'Reminders', ownerOnly: true },
+  { key: 'operations', label: 'Operations', ownerOnly: true },
   { key: 'sharing', label: 'Sharing', ownerOnly: true },
   { key: 'integrations', label: 'Integrations', ownerOnly: true },
   { key: 'appearance', label: 'Appearance', ownerOnly: false },
@@ -64,6 +66,7 @@ export function Settings() {
           {active === 'company' && <CompanyPanel />}
           {active === 'template' && <TemplatePanel />}
           {active === 'reminders' && <RemindersPanel />}
+          {active === 'operations' && <OperationsPanel />}
           {active === 'sharing' && <SharingPanel />}
           {active === 'integrations' && <IntegrationsPanel />}
           {active === 'appearance' && <AppearancePanel />}
@@ -73,6 +76,59 @@ export function Settings() {
   )
 }
 
+/** Operations (D28) — the running-the-service knobs: SMS gateway + thresholds + ticket SLA.
+ *  All are DB settings resolved by the app (config over code); editing here is the whole point. */
+function OperationsPanel() {
+  const toast = useToast()
+  const [s, setS] = useState<OperationsSettings | undefined>()
+  const [saving, setSaving] = useState(false)
+
+  useEffect(() => {
+    getOperationsSettings().then(setS).catch((e: Error) => toast.err(e.message))
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [])
+
+  const save = () => {
+    if (saving || s === undefined) return
+    setSaving(true)
+    putOperationsSettings(s)
+      .then((next) => { setS(next); toast.ok('Operations settings saved.') })
+      .catch((e: Error) => toast.err(e.message))
+      .finally(() => setSaving(false))
+  }
+
+  return (
+    <div>
+      <h2>Operations</h2>
+      <p className="wf-page-desc">The knobs behind the SMS balance screen and the ticket desk — change them here, no release needed.</p>
+      {s === undefined ? <Skeleton rows={4} /> : (
+        <>
+          <FormGrid>
+            <FormField label="SMS balance API URL" wide>
+              <input className="wf" value={s.smsBalanceApiUrl}
+                onChange={(e) => setS({ ...s, smsBalanceApiUrl: e.target.value })} />
+              <span style={{ display: 'block', fontSize: 12, opacity: 0.6, marginTop: 4 }}>The provider panel HQ polls for each SMS account’s balance. Public host only.</span>
+            </FormField>
+            <FormField label="SMS low-balance threshold">
+              <input className="wf num" type="number" min={0} value={s.smsLowThreshold}
+                onChange={(e) => setS({ ...s, smsLowThreshold: Number(e.target.value) })} />
+              <span style={{ display: 'block', fontSize: 12, opacity: 0.6, marginTop: 4 }}>Below this many SMS a client is flagged “low” and shows in the upsell list.</span>
+            </FormField>
+            <FormField label="Ticket SLA (days)">
+              <input className="wf num" type="number" min={1} value={s.ticketSlaDays}
+                onChange={(e) => setS({ ...s, ticketSlaDays: Number(e.target.value) })} />
+              <span style={{ display: 'block', fontSize: 12, opacity: 0.6, marginTop: 4 }}>A still-open ticket older than this is marked overdue on the desk.</span>
+            </FormField>
+          </FormGrid>
+          <Toolbar>
+            <Button pill tone="primary" disabled={saving} onClick={save}>{saving ? 'Saving…' : 'Save'}</Button>
+          </Toolbar>
+        </>
+      )}
+    </div>
+  )
+}
+
 /** Company identity — same field list as the letterhead template's Company section
  *  (`COMPANY_FIELDS`, imported so the two never drift apart). */
 function CompanyPanel() {
diff --git a/apps/hq/src/api.ts b/apps/hq/src/api.ts
index e0ce108..480dfce 100644
--- a/apps/hq/src/api.ts
+++ b/apps/hq/src/api.ts
@@ -48,7 +48,7 @@ import {
   listInteractionTypes, updateInteraction, type CreateInteractionInput, type InteractionPatch,
 } from './repos-interactions'
 import {
-  dismissReminder, getNumberSetting, getReminder, insertSchedule, listQueue, listSchedules, setSetting,
+  dismissReminder, getNumberSetting, getSetting, getReminder, insertSchedule, listQueue, listSchedules, setSetting,
   type QueueOpts, type ReminderStatus,
 } from './repos-reminders'
 import { sendReminder, reminderContext, type SendReminderDeps } from './send-reminder'
@@ -62,7 +62,8 @@ import { clientProfitability, duesAging, gstSummary, moduleRevenue, type DateRan
 import { listUsageRateCards, setUsageRateCard } from './repos-rate-card'
 import { renewalsDue, generateModuleRenewalQuote } from './repos-renewals'
 import { misCockpit } from './repos-mis'
-import { smsBalances, refreshSmsBalance, refreshAllSmsBalances } from './repos-sms'
+import { smsBalances, refreshSmsBalance, refreshAllSmsBalances, DEFAULT_SMS_BALANCE_API } from './repos-sms'
+import { assertSafeGatewayUrl } from './sms-gateway'
 import { makeRateLimiter } from './rate-limit'
 import {
   addProjectMilestone, bulkSetMilestone, ensureProjectMilestones, listProjectMilestones, milestoneBoard,
@@ -1663,6 +1664,47 @@ export function apiRouter(
       res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
     }
   })
+  // ---------- operations knobs (owner): SMS gateway + thresholds + ticket SLA (D28) ----------
+  r.get('/settings/operations', requireAuth, requireOwner, async (_req, res) => {
+    try {
+      res.json({
+        ok: true,
+        smsBalanceApiUrl: (await getSetting(db, 'sms.balance_api_url')) ?? DEFAULT_SMS_BALANCE_API,
+        smsLowThreshold: await getNumberSetting(db, 'sms.low_balance_threshold', 10000),
+        ticketSlaDays: await getNumberSetting(db, 'ticket.sla_days', 7),
+      })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
+  r.put('/settings/operations', requireAuth, requireOwner, async (req, res) => {
+    const b = req.body as { smsBalanceApiUrl?: unknown; smsLowThreshold?: unknown; ticketSlaDays?: unknown }
+    try {
+      if (b.smsBalanceApiUrl !== undefined) {
+        const url = String(b.smsBalanceApiUrl).trim()
+        if (url !== '') assertSafeGatewayUrl(url) // reject internal/loopback targets before storing
+        await setSetting(db, staffId(res), 'sms.balance_api_url', url)
+      }
+      if (b.smsLowThreshold !== undefined) {
+        const n = Number(b.smsLowThreshold)
+        if (!Number.isInteger(n) || n < 0) throw new Error('Low-balance threshold must be a whole number ≥ 0')
+        await setSetting(db, staffId(res), 'sms.low_balance_threshold', String(n))
+      }
+      if (b.ticketSlaDays !== undefined) {
+        const n = Number(b.ticketSlaDays)
+        if (!Number.isInteger(n) || n < 1) throw new Error('Ticket SLA must be a whole number of days ≥ 1')
+        await setSetting(db, staffId(res), 'ticket.sla_days', String(n))
+      }
+      res.json({
+        ok: true,
+        smsBalanceApiUrl: (await getSetting(db, 'sms.balance_api_url')) ?? DEFAULT_SMS_BALANCE_API,
+        smsLowThreshold: await getNumberSetting(db, 'sms.low_balance_threshold', 10000),
+        ticketSlaDays: await getNumberSetting(db, 'ticket.sla_days', 7),
+      })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
   r.put('/settings/company', requireAuth, requireOwner, async (req, res) => {
     const body = req.body as Record<string, unknown>
     try {