diff --git a/server/supabase/functions/admin-subscriptions/index.ts b/server/supabase/functions/admin-subscriptions/index.ts
index ad2feb8..18c9f0c 100644
--- a/server/supabase/functions/admin-subscriptions/index.ts
+++ b/server/supabase/functions/admin-subscriptions/index.ts
@@ -8,7 +8,6 @@ import {
   actorEmail,
   adminErrorResponse,
   adminJsonResponse,
-  adminRpcError,
   parsePagination,
   parseSubscriptionMutationRequest,
   readAdminJson,
@@ -19,6 +18,7 @@ import {
   validateQueryKeys,
   validateSubscriptionRpcResult,
 } from '../_shared/admin-contract.ts'
+import { subscriptionRpcError } from './rpc-error.ts'
 
 const SUBSCRIPTION_COLUMNS = 'id, user_id, tier, status, provider, payment_provider, current_period_start, current_period_end, overage_credits, admin_note, cancel_at, created_at, updated_at'
 
@@ -82,7 +82,7 @@ async function mutateSubscription(req: Request, action: SubscriptionAction): Pro
     p_admin_note: mutation.adminNote ?? null,
     p_memo: mutation.memo,
   })
-  if (error) throw adminRpcError(error)
+  if (error) throw subscriptionRpcError(error)
   const response = validateSubscriptionRpcResult(data, mutation)
   return adminJsonResponse(response, corsHeaders, action === 'create' ? 201 : 200)
 }
diff --git a/server/supabase/functions/admin-subscriptions/rpc-error.test.ts b/server/supabase/functions/admin-subscriptions/rpc-error.test.ts
new file mode 100644
index 0000000..831cb43
--- /dev/null
+++ b/server/supabase/functions/admin-subscriptions/rpc-error.test.ts
@@ -0,0 +1,18 @@
+import { PROVIDER_MANAGED_SUBSCRIPTION, subscriptionRpcError } from './rpc-error.ts'
+
+function assert(condition: boolean, message: string): asserts condition {
+  if (!condition) throw new Error(message)
+}
+
+Deno.test('provider-owned subscription edits surface as a specific 409', () => {
+  const error = subscriptionRpcError({ code: '23514', message: 'provider_managed_subscription' })
+  assert(error.status === 409, `status 409, got ${error.status}`)
+  assert(error.code === PROVIDER_MANAGED_SUBSCRIPTION, `code ${error.code}`)
+})
+
+Deno.test('other subscription RPC errors keep the shared admin mapping', () => {
+  const forbidden = subscriptionRpcError({ code: '42501', message: 'admin_role_required' })
+  assert(forbidden.status === 403 && forbidden.code === 'admin_role_required', 'admin role mapping kept')
+  const conflict = subscriptionRpcError({ code: '23514', message: 'some_other_check' })
+  assert(conflict.status === 409 && conflict.code === 'admin_operation_conflict', 'generic conflict kept')
+})
diff --git a/server/supabase/functions/admin-subscriptions/rpc-error.ts b/server/supabase/functions/admin-subscriptions/rpc-error.ts
new file mode 100644
index 0000000..4e96c08
--- /dev/null
+++ b/server/supabase/functions/admin-subscriptions/rpc-error.ts
@@ -0,0 +1,20 @@
+// server/supabase/functions/admin-subscriptions/rpc-error.ts
+// admin_mutate_subscription_v1 오류를 공개 오류 코드로 바꾼다. 구독 전용 거절 사유를
+// 먼저 판별하고, 나머지는 공통 관리자 RPC 매핑(adminRpcError)에 맡긴다.
+
+import { AdminPublicError, adminRpcError } from '../_shared/admin-contract.ts'
+
+type AdminRpcErrorLike = Parameters<typeof adminRpcError>[0]
+
+/**
+ * 결제 사업자(Payple·스토어)가 소유한 구독의 등급·상태·기간을 관리자 화면에서 바꾸려 할 때
+ * SQL이 던지는 사유. 사업자가 청구 조건의 정본이므로 관리자 수정은 충돌(409)로 거절한다.
+ */
+export const PROVIDER_MANAGED_SUBSCRIPTION = 'provider_managed_subscription'
+
+export function subscriptionRpcError(error: AdminRpcErrorLike): AdminPublicError {
+  if ((error.message ?? '').includes(PROVIDER_MANAGED_SUBSCRIPTION)) {
+    return new AdminPublicError(409, PROVIDER_MANAGED_SUBSCRIPTION)
+  }
+  return adminRpcError(error)
+}
diff --git a/server/supabase/functions/payple-renew/index.ts b/server/supabase/functions/payple-renew/index.ts
index 9075516..70b3edf 100644
--- a/server/supabase/functions/payple-renew/index.ts
+++ b/server/supabase/functions/payple-renew/index.ts
@@ -9,10 +9,12 @@ import {
 import { createPaypleRenewalGateway, createSupabaseRenewalStore } from './adapters.ts'
 import {
   normalizeRenewalCandidate,
+  type RenewableTier,
   type RenewalDeps,
   type RenewalResult,
   renewSubscription,
 } from './renewal.ts'
+import { latestPaidTierByUser, withPaidTier } from './paid-tier.ts'
 
 type ServiceClient = ReturnType<typeof createServiceRoleClient>
 
@@ -94,6 +96,32 @@ async function selectDueRenewals(
   return (data ?? []) as Record<string, unknown>[]
 }
 
+const PAID_TIER_QUERY_CHUNK = 100
+
+/**
+ * 갱신 대상 사용자별로 마지막으로 반영된 Payple 결제 등급을 읽는다.
+ * 청구 금액의 정본은 이 원장이다 — subscriptions.tier는 청구 근거로 쓰지 않는다.
+ */
+async function loadLastPaidTiers(
+  serviceClient: ServiceClient,
+  userIds: readonly string[],
+): Promise<Map<string, RenewableTier>> {
+  const rows: Record<string, unknown>[] = []
+  for (let offset = 0; offset < userIds.length; offset += PAID_TIER_QUERY_CHUNK) {
+    const { data, error } = await serviceClient
+      .from('payment_provider_operations')
+      .select('user_id, requested_tier, updated_at, created_at')
+      .eq('provider', 'payple')
+      .eq('state', 'applied')
+      .in('operation_type', ['checkout', 'renewal'])
+      .not('requested_tier', 'is', null)
+      .in('user_id', userIds.slice(offset, offset + PAID_TIER_QUERY_CHUNK))
+    if (error) throw new Error('renewal_paid_tier_query_failed')
+    rows.push(...((data ?? []) as Record<string, unknown>[]))
+  }
+  return latestPaidTierByUser(rows)
+}
+
 export async function paypleRenewHandler(req: Request): Promise<Response> {
   if (req.method === 'OPTIONS') return new Response('ok', { headers: corsHeaders })
   if (req.method !== 'POST') return jsonResponse({ error: 'method_not_allowed' }, 405)
@@ -109,6 +137,11 @@ export async function paypleRenewHandler(req: Request): Promise<Response> {
       return jsonResponse({ renewed: 0, failed: 0, expired, results })
     }
 
+    const userIds = dueRenewals
+      .map((row) => row.user_id)
+      .filter((userId): userId is string => typeof userId === 'string')
+    const paidTiers = await loadLastPaidTiers(serviceClient, userIds)
+
     const deps: RenewalDeps = {
       store: createSupabaseRenewalStore(serviceClient),
       gateway: await createPaypleRenewalGateway(getPaypleConfig()),
@@ -117,7 +150,7 @@ export async function paypleRenewHandler(req: Request): Promise<Response> {
     }
 
     for (const row of dueRenewals) {
-      const candidate = normalizeRenewalCandidate(row)
+      const candidate = normalizeRenewalCandidate(withPaidTier(row, paidTiers))
       if (!candidate) {
         results.push({
           userId: typeof row.user_id === 'string' ? row.user_id : '',
diff --git a/server/supabase/functions/payple-renew/paid-tier.test.ts b/server/supabase/functions/payple-renew/paid-tier.test.ts
new file mode 100644
index 0000000..2773a9a
--- /dev/null
+++ b/server/supabase/functions/payple-renew/paid-tier.test.ts
@@ -0,0 +1,111 @@
+import { latestPaidTierByUser, withPaidTier } from './paid-tier.ts'
+import {
+  type ChargeRequest,
+  normalizeRenewalCandidate,
+  type RenewalDeps,
+  type RenewalPaymentApplication,
+  renewSubscription,
+} from './renewal.ts'
+import { TIER_PRICE } from '../_shared/payple.ts'
+
+function assert(condition: boolean, message: string): asserts condition {
+  if (!condition) throw new Error(message)
+}
+
+const USER = 'user0019-0000-0000-0000-000000000000'
+const OTHER_USER = 'user0020-0000-0000-0000-000000000000'
+const ORDER = 'D3RO-20260928100000-user0019-cccccccc'
+
+/** A Payple Pro subscriber whose row tier a back-office edit rewrote to pro_plus. */
+const tamperedDueRow: Record<string, unknown> = {
+  user_id: USER,
+  tier: 'pro_plus',
+  payple_payer_id: 'payer-19',
+  provider_resource_id: 'payer-19',
+  current_period_end: '2026-09-27T00:00:00.000Z',
+  renewal_failures: 0,
+}
+
+const appliedOperations: Record<string, unknown>[] = [
+  { user_id: USER, requested_tier: 'pro', updated_at: '2026-08-27T00:00:05.000Z', created_at: '2026-08-27T00:00:00.000Z' },
+  { user_id: OTHER_USER, requested_tier: 'pro_plus', updated_at: '2026-09-01T00:00:00.000Z', created_at: '2026-09-01T00:00:00.000Z' },
+]
+
+function chargingHarness(): { deps: RenewalDeps; charges: ChargeRequest[]; applied: RenewalPaymentApplication[] } {
+  const charges: ChargeRequest[] = []
+  const applied: RenewalPaymentApplication[] = []
+  const deps: RenewalDeps = {
+    now: () => new Date('2026-09-28T01:00:00.000Z'),
+    newOrderId: () => ORDER,
+    store: {
+      reserveRenewal: () => Promise.resolve({ kind: 'created', operationId: 'op-19' }),
+      getOperation: () => Promise.resolve(null),
+      markOperation: () => Promise.resolve(true),
+      recordRenewalFailure: () => Promise.resolve(true),
+      applyRenewalPayment: (application) => {
+        applied.push(application)
+        return Promise.resolve({ applied: true, duplicate: false })
+      },
+    },
+    gateway: {
+      charge: (request) => {
+        charges.push(request)
+        return Promise.resolve({ orderId: request.orderId, total: String(request.amount) })
+      },
+      lookup: () => Promise.resolve({ kind: 'unknown' }),
+    },
+  }
+  return { deps, charges, applied }
+}
+
+// ── 회귀: 관리자 등급 수정이 다음 갱신 청구 금액을 바꾸던 버그 ─────────
+
+Deno.test('renewal charges the tier the customer last paid for, not an edited row tier', async () => {
+  const candidate = normalizeRenewalCandidate(
+    withPaidTier(tamperedDueRow, latestPaidTierByUser(appliedOperations)),
+  )
+  assert(candidate !== null, 'candidate is valid')
+  const { deps, charges, applied } = chargingHarness()
+
+  const result = await renewSubscription(deps, candidate)
+
+  assert(result.success, `renewal succeeds: ${JSON.stringify(result)}`)
+  assert(charges.length === 1, 'charged once')
+  assert(charges[0].amount === TIER_PRICE.pro, `charged the pro price, got ${charges[0].amount}`)
+  assert(applied.length === 1 && applied[0].candidate.tier === 'pro', 'entitlement renewed at the paid tier')
+})
+
+Deno.test('legacy subscriptions without a payment ledger entry keep their row tier', () => {
+  const row = { ...tamperedDueRow, user_id: 'legacy-user', tier: 'pro' }
+  const adjusted = withPaidTier(row, latestPaidTierByUser(appliedOperations))
+  assert(adjusted === row, 'row is returned unchanged')
+  assert(normalizeRenewalCandidate(adjusted)?.tier === 'pro', 'legacy tier kept')
+})
+
+Deno.test('latest applied payment operation wins per user', () => {
+  const tiers = latestPaidTierByUser([
+    { user_id: USER, requested_tier: 'pro', updated_at: '2026-07-01T00:00:00.000Z', created_at: '2026-07-01T00:00:00.000Z' },
+    { user_id: USER, requested_tier: 'pro_plus', updated_at: '2026-09-01T00:00:00.000Z', created_at: '2026-09-01T00:00:00.000Z' },
+    { user_id: USER, requested_tier: 'pro', updated_at: '2026-08-01T00:00:00.000Z', created_at: '2026-08-01T00:00:00.000Z' },
+  ])
+  assert(tiers.get(USER) === 'pro_plus', 'most recently applied upgrade is charged')
+})
+
+Deno.test('same applied time falls back to the later created operation', () => {
+  const tiers = latestPaidTierByUser([
+    { user_id: USER, requested_tier: 'pro_plus', updated_at: '2026-09-01T00:00:00.000Z', created_at: '2026-08-31T00:00:00.000Z' },
+    { user_id: USER, requested_tier: 'pro', updated_at: '2026-09-01T00:00:00.000Z', created_at: '2026-09-01T00:00:00.000Z' },
+  ])
+  assert(tiers.get(USER) === 'pro', 'later-created operation wins the tie')
+})
+
+Deno.test('malformed ledger rows are ignored', () => {
+  const tiers = latestPaidTierByUser([
+    { user_id: USER, requested_tier: 'free', updated_at: '2026-09-01T00:00:00.000Z' },
+    { user_id: USER, requested_tier: null, updated_at: '2026-09-02T00:00:00.000Z' },
+    { user_id: USER, requested_tier: 'pro_plus', updated_at: 'not-a-date' },
+    { user_id: 42, requested_tier: 'pro', updated_at: '2026-09-03T00:00:00.000Z' },
+    { user_id: USER, requested_tier: 'pro', updated_at: '2026-08-01T00:00:00.000Z' },
+  ])
+  assert(tiers.size === 1 && tiers.get(USER) === 'pro', 'only the valid row counts')
+})
diff --git a/server/supabase/functions/payple-renew/paid-tier.ts b/server/supabase/functions/payple-renew/paid-tier.ts
new file mode 100644
index 0000000..8e27fb4
--- /dev/null
+++ b/server/supabase/functions/payple-renew/paid-tier.ts
@@ -0,0 +1,58 @@
+// server/supabase/functions/payple-renew/paid-tier.ts
+// 갱신 청구 등급 정책 — 청구 금액은 고객이 실제로 결제한 등급에서 정한다.
+//
+// subscriptions.tier는 관리자 화면·동기화 트리거 등 여러 경로에서 바뀔 수 있는 엔타이틀먼트
+// 값이다. 저장된 빌링키로 청구할 금액을 이 값에서 읽으면, 등급 수정 한 번으로 고객이 동의하지
+// 않은 금액이 청구된다. 그래서 갱신은 마지막으로 반영(applied)된 Payple 결제 작업의
+// requested_tier를 정본으로 삼는다. 결제 작업 원장이 생기기 전의 레거시 구독처럼 기록이
+// 없을 때만 행의 tier를 그대로 쓴다.
+
+import type { RenewableTier } from './renewal.ts'
+
+function renewableTier(value: unknown): RenewableTier | null {
+  return value === 'pro' || value === 'pro_plus' ? value : null
+}
+
+function timestampOf(value: unknown): number {
+  if (typeof value !== 'string') return Number.NaN
+  return new Date(value).getTime()
+}
+
+/**
+ * payment_provider_operations 행(state='applied', 결제 유형)에서 사용자별로 가장 나중에
+ * 반영된 작업의 등급을 고른다. 반영 시각은 updated_at(반영 후에는 더 바뀌지 않는다),
+ * 같으면 created_at으로 가린다. 형식이 맞지 않는 행은 무시한다.
+ */
+export function latestPaidTierByUser(
+  rows: readonly Record<string, unknown>[],
+): Map<string, RenewableTier> {
+  const latest = new Map<string, { tier: RenewableTier; appliedAt: number; createdAt: number }>()
+  for (const row of rows) {
+    const userId = typeof row.user_id === 'string' ? row.user_id : ''
+    const tier = renewableTier(row.requested_tier)
+    const appliedAt = timestampOf(row.updated_at)
+    if (!userId || !tier || !Number.isFinite(appliedAt)) continue
+    const createdAt = timestampOf(row.created_at)
+    const current = latest.get(userId)
+    const newer = !current
+      || appliedAt > current.appliedAt
+      || (appliedAt === current.appliedAt
+        && Number.isFinite(createdAt)
+        && (!Number.isFinite(current.createdAt) || createdAt > current.createdAt))
+    if (newer) latest.set(userId, { tier, appliedAt, createdAt })
+  }
+  return new Map([...latest].map(([userId, entry]) => [userId, entry.tier]))
+}
+
+/**
+ * 갱신 후보 행의 tier를 고객이 마지막으로 결제한 등급으로 맞춘다.
+ * 결제 기록이 없으면 행을 그대로 돌려준다(레거시 호환).
+ */
+export function withPaidTier(
+  row: Record<string, unknown>,
+  paidTiers: ReadonlyMap<string, RenewableTier>,
+): Record<string, unknown> {
+  const userId = typeof row.user_id === 'string' ? row.user_id : ''
+  const paidTier = userId ? paidTiers.get(userId) : undefined
+  return paidTier ? { ...row, tier: paidTier } : row
+}
diff --git a/server/supabase/migrations/20260928190000_admin_subscription_provider_guard.sql b/server/supabase/migrations/20260928190000_admin_subscription_provider_guard.sql
new file mode 100644
index 0000000..7917690
--- /dev/null
+++ b/server/supabase/migrations/20260928190000_admin_subscription_provider_guard.sql
@@ -0,0 +1,196 @@
+-- Back-office subscription edits must not rewrite provider-owned billing terms.
+--
+-- admin_mutate_subscription_v1 (20260821000023) let a manager PATCH the tier,
+-- status and period end of a subscription that a payment provider owns. For a
+-- Payple subscriber the row kept provider='payple', auto_renewing=true and its
+-- billing key, so the next payple-renew run charged the stored card the price
+-- of the edited tier. Admin 'delete' likewise left provider='payple' (or
+-- google_play), which blocks the customer from buying again on the web.
+--
+-- This redefinition keeps the signature, idempotency contract and audit shape,
+-- and changes two branches:
+--   * update: on a provider-owned row (provider not in 'none'/'admin') a change
+--     of tier, status or period end is rejected with
+--     'provider_managed_subscription'. Notes and overage credits stay editable.
+--     The admin form edits the period end at day granularity, so a value on
+--     the same UTC date as the stored one is treated as unchanged and the
+--     stored instant is kept.
+--   * delete: releases provider ownership the same way a non-entitled provider
+--     event does (provider 'none', no resource, not auto-renewing, no store
+--     product), so renewals stop and the customer can purchase again.
+
+BEGIN;
+
+CREATE OR REPLACE FUNCTION public.admin_mutate_subscription_v1(
+  p_actor_email text,
+  p_idempotency_key uuid,
+  p_action text,
+  p_user_id uuid,
+  p_tier text DEFAULT NULL,
+  p_status text DEFAULT NULL,
+  p_current_period_end timestamptz DEFAULT NULL,
+  p_overage_credits integer DEFAULT NULL,
+  p_admin_note text DEFAULT NULL,
+  p_memo text DEFAULT NULL
+)
+RETURNS jsonb
+LANGUAGE plpgsql
+SECURITY DEFINER
+SET search_path = pg_catalog, public, auth, extensions
+AS $$
+DECLARE
+  actor record;
+  before_subscription public.subscriptions%ROWTYPE;
+  after_subscription public.subscriptions%ROWTYPE;
+  request_payload jsonb;
+  request_digest text;
+  existing_request public.admin_operation_requests%ROWTYPE;
+  inserted boolean;
+  result jsonb;
+  before_snapshot jsonb;
+  after_snapshot jsonb;
+  provider_managed boolean;
+  next_period_end timestamptz;
+BEGIN
+  SELECT * INTO actor FROM public.resolve_external_admin_actor_v1(p_actor_email, 'manager');
+  IF p_action NOT IN ('create', 'update', 'delete') OR p_idempotency_key IS NULL OR p_user_id IS NULL THEN
+    RAISE EXCEPTION 'invalid_subscription_operation' USING ERRCODE = '22023';
+  END IF;
+  IF p_action IN ('create', 'delete') AND actor.actor_role = 'manager' THEN
+    RAISE EXCEPTION 'admin_role_required' USING ERRCODE = '42501';
+  END IF;
+  IF p_memo IS NULL OR char_length(trim(p_memo)) NOT BETWEEN 3 AND 1000 THEN
+    RAISE EXCEPTION 'memo_must_be_3_to_1000_characters' USING ERRCODE = '22023';
+  END IF;
+  IF p_tier IS NOT NULL AND p_tier NOT IN ('free', 'pro', 'pro_plus') THEN
+    RAISE EXCEPTION 'invalid_subscription_tier' USING ERRCODE = '22023';
+  END IF;
+  IF p_status IS NOT NULL AND p_status NOT IN ('active', 'canceled', 'past_due', 'expired') THEN
+    RAISE EXCEPTION 'invalid_subscription_status' USING ERRCODE = '22023';
+  END IF;
+  IF p_overage_credits IS NOT NULL AND (p_overage_credits < 0 OR p_overage_credits > 1000000) THEN
+    RAISE EXCEPTION 'invalid_overage_credits' USING ERRCODE = '22023';
+  END IF;
+  IF p_admin_note IS NOT NULL AND char_length(p_admin_note) > 2000 THEN
+    RAISE EXCEPTION 'admin_note_too_long' USING ERRCODE = '22023';
+  END IF;
+  IF NOT EXISTS (SELECT 1 FROM public.profiles WHERE id = p_user_id) THEN
+    RAISE EXCEPTION 'target_user_not_found' USING ERRCODE = 'P0002';
+  END IF;
+
+  request_payload := jsonb_build_object(
+    'action', p_action, 'user', p_user_id, 'tier', p_tier, 'status', p_status,
+    'periodEnd', p_current_period_end, 'credits', p_overage_credits,
+    'note', p_admin_note, 'memo', trim(p_memo)
+  );
+  request_digest := encode(extensions.digest(request_payload::text, 'sha256'), 'hex');
+  INSERT INTO public.admin_operation_requests(actor_id, idempotency_key, operation, request_hash)
+  VALUES (actor.actor_id, p_idempotency_key, 'subscription.' || p_action, request_digest)
+  ON CONFLICT DO NOTHING
+  RETURNING true INTO inserted;
+  IF NOT coalesce(inserted, false) THEN
+    SELECT * INTO existing_request FROM public.admin_operation_requests
+    WHERE actor_id = actor.actor_id AND idempotency_key = p_idempotency_key;
+    IF existing_request.operation <> ('subscription.' || p_action) OR existing_request.request_hash <> request_digest THEN
+      RAISE EXCEPTION 'idempotency_key_reused_with_different_request' USING ERRCODE = '22023';
+    END IF;
+    IF existing_request.response_data IS NULL THEN
+      RAISE EXCEPTION 'operation_in_progress' USING ERRCODE = '55P03';
+    END IF;
+    RETURN existing_request.response_data;
+  END IF;
+
+  SELECT * INTO before_subscription FROM public.subscriptions WHERE user_id = p_user_id FOR UPDATE;
+  IF p_action = 'create' THEN
+    IF before_subscription.id IS NOT NULL THEN
+      RAISE EXCEPTION 'subscription_already_exists' USING ERRCODE = '23505';
+    END IF;
+    IF p_tier IS NULL THEN RAISE EXCEPTION 'tier_required' USING ERRCODE = '22023'; END IF;
+    INSERT INTO public.subscriptions(user_id, tier, status, provider, payment_provider,
+      current_period_start, current_period_end, overage_credits, admin_note, created_at, updated_at)
+    VALUES (p_user_id, p_tier, coalesce(p_status, 'active'), 'none', 'none', now(),
+      p_current_period_end, coalesce(p_overage_credits, 0), p_admin_note, now(), now())
+    RETURNING * INTO after_subscription;
+  ELSIF p_action = 'update' THEN
+    IF before_subscription.id IS NULL THEN RAISE EXCEPTION 'subscription_not_found' USING ERRCODE = 'P0002'; END IF;
+    provider_managed := coalesce(before_subscription.provider, 'none') NOT IN ('none', 'admin');
+    IF provider_managed THEN
+      IF (p_tier IS NOT NULL AND p_tier IS DISTINCT FROM before_subscription.tier)
+         OR (p_status IS NOT NULL AND p_status IS DISTINCT FROM before_subscription.status)
+         OR (p_current_period_end IS NOT NULL AND (
+               before_subscription.current_period_end IS NULL
+               OR (p_current_period_end AT TIME ZONE 'UTC')::date
+                  <> (before_subscription.current_period_end AT TIME ZONE 'UTC')::date
+             )) THEN
+        RAISE EXCEPTION 'provider_managed_subscription' USING ERRCODE = '23514';
+      END IF;
+      next_period_end := before_subscription.current_period_end;
+    ELSE
+      next_period_end := coalesce(p_current_period_end, before_subscription.current_period_end);
+    END IF;
+    UPDATE public.subscriptions SET
+      tier = coalesce(p_tier, tier),
+      status = coalesce(p_status, status),
+      current_period_end = next_period_end,
+      overage_credits = coalesce(p_overage_credits, overage_credits),
+      admin_note = coalesce(p_admin_note, admin_note),
+      updated_at = now()
+    WHERE user_id = p_user_id RETURNING * INTO after_subscription;
+  ELSE
+    IF before_subscription.id IS NULL THEN RAISE EXCEPTION 'subscription_not_found' USING ERRCODE = 'P0002'; END IF;
+    UPDATE public.subscriptions SET tier = 'free', status = 'expired', cancel_at = now(),
+      provider = 'none',
+      provider_resource_id = NULL,
+      auto_renewing = false,
+      store_product_id = NULL,
+      store_purchase_id = NULL,
+      admin_note = '[DELETED] ' || trim(p_memo), updated_at = now()
+    WHERE user_id = p_user_id RETURNING * INTO after_subscription;
+  END IF;
+
+  UPDATE public.profiles SET tier = after_subscription.tier, updated_at = now() WHERE id = p_user_id;
+  before_snapshot := CASE WHEN before_subscription.id IS NULL THEN NULL ELSE jsonb_build_object(
+    'id', before_subscription.id,
+    'user_id', before_subscription.user_id,
+    'tier', before_subscription.tier,
+    'status', before_subscription.status,
+    'provider', before_subscription.provider,
+    'payment_provider', before_subscription.payment_provider,
+    'current_period_start', before_subscription.current_period_start,
+    'current_period_end', before_subscription.current_period_end,
+    'overage_credits', before_subscription.overage_credits,
+    'admin_note', before_subscription.admin_note,
+    'cancel_at', before_subscription.cancel_at,
+    'created_at', before_subscription.created_at,
+    'updated_at', before_subscription.updated_at
+  ) END;
+  after_snapshot := jsonb_build_object(
+    'id', after_subscription.id,
+    'user_id', after_subscription.user_id,
+    'tier', after_subscription.tier,
+    'status', after_subscription.status,
+    'provider', after_subscription.provider,
+    'payment_provider', after_subscription.payment_provider,
+    'current_period_start', after_subscription.current_period_start,
+    'current_period_end', after_subscription.current_period_end,
+    'overage_credits', after_subscription.overage_credits,
+    'admin_note', after_subscription.admin_note,
+    'cancel_at', after_subscription.cancel_at,
+    'created_at', after_subscription.created_at,
+    'updated_at', after_subscription.updated_at
+  );
+  INSERT INTO public.audit_log(admin_id, action, target_type, target_id, before_data, after_data, memo)
+  VALUES (actor.actor_id, 'subscription.' || p_action, 'subscription', p_user_id,
+    before_snapshot, after_snapshot, trim(p_memo));
+
+  result := jsonb_build_object('success', true, 'subscription', after_snapshot);
+  UPDATE public.admin_operation_requests SET response_data = result, completed_at = now()
+  WHERE actor_id = actor.actor_id AND idempotency_key = p_idempotency_key;
+  RETURN result;
+END;
+$$;
+
+REVOKE ALL ON FUNCTION public.admin_mutate_subscription_v1(text, uuid, text, uuid, text, text, timestamptz, integer, text, text) FROM PUBLIC, anon, authenticated;
+GRANT EXECUTE ON FUNCTION public.admin_mutate_subscription_v1(text, uuid, text, uuid, text, text, timestamptz, integer, text, text) TO service_role;
+
+COMMIT;
diff --git a/server/supabase/tests/admin-subscription-provider-guard.integration.sql b/server/supabase/tests/admin-subscription-provider-guard.integration.sql
new file mode 100644
index 0000000..806c1a5
--- /dev/null
+++ b/server/supabase/tests/admin-subscription-provider-guard.integration.sql
@@ -0,0 +1,200 @@
+\set ON_ERROR_STOP on
+
+-- Regression: back-office subscription edits must not rewrite the billing terms
+-- of a provider-owned (Payple / store) subscription, and admin delete must
+-- release provider ownership so the customer can purchase again.
+-- Before 20260928190000 a manager PATCH of tier='pro_plus' on an auto-renewing
+-- Payple Pro row was accepted, and payple-renew then charged the pro_plus price.
+
+BEGIN;
+
+CREATE OR REPLACE FUNCTION pg_temp.assert_true(condition boolean, message text)
+RETURNS void
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  IF condition IS NOT TRUE THEN
+    RAISE EXCEPTION 'assertion_failed: %', message;
+  END IF;
+END;
+$$;
+
+INSERT INTO auth.users (
+  id, aud, role, email, encrypted_password, email_confirmed_at,
+  raw_app_meta_data, raw_user_meta_data, created_at, updated_at
+) VALUES
+  (
+    '41900000-0000-4000-8000-000000000001', 'authenticated', 'authenticated',
+    'guard-manager@example.invalid', crypt('fixture-password', gen_salt('bf')), now(),
+    '{"provider":"email","providers":["email"]}'::jsonb, '{}'::jsonb, now(), now()
+  ),
+  (
+    '41900000-0000-4000-8000-000000000002', 'authenticated', 'authenticated',
+    'guard-admin@example.invalid', crypt('fixture-password', gen_salt('bf')), now(),
+    '{"provider":"email","providers":["email"]}'::jsonb, '{}'::jsonb, now(), now()
+  ),
+  (
+    '41900000-0000-4000-8000-000000000003', 'authenticated', 'authenticated',
+    'guard-payple-customer@example.invalid', crypt('fixture-password', gen_salt('bf')), now(),
+    '{"provider":"email","providers":["email"]}'::jsonb, '{}'::jsonb, now(), now()
+  ),
+  (
+    '41900000-0000-4000-8000-000000000004', 'authenticated', 'authenticated',
+    'guard-comp-customer@example.invalid', crypt('fixture-password', gen_salt('bf')), now(),
+    '{"provider":"email","providers":["email"]}'::jsonb, '{}'::jsonb, now(), now()
+  );
+
+UPDATE public.profiles SET role = 'manager' WHERE id = '41900000-0000-4000-8000-000000000001';
+UPDATE public.profiles SET role = 'admin' WHERE id = '41900000-0000-4000-8000-000000000002';
+
+INSERT INTO public.subscriptions (user_id, tier, status, provider, payment_provider)
+VALUES
+  ('41900000-0000-4000-8000-000000000003', 'free', 'active', 'none', 'none'),
+  ('41900000-0000-4000-8000-000000000004', 'free', 'active', 'none', 'none')
+ON CONFLICT (user_id) DO NOTHING;
+
+UPDATE public.subscriptions
+   SET tier = 'pro',
+       status = 'active',
+       provider = 'payple',
+       provider_resource_id = 'payple-guard-fixture-resource',
+       payple_payer_id = 'payple-guard-fixture-payer',
+       auto_renewing = true,
+       current_period_start = '2026-09-15T03:12:45Z',
+       current_period_end = '2026-10-15T03:12:45Z'
+ WHERE user_id = '41900000-0000-4000-8000-000000000003';
+
+UPDATE public.subscriptions
+   SET tier = 'free', status = 'active', provider = 'none', auto_renewing = NULL
+ WHERE user_id = '41900000-0000-4000-8000-000000000004';
+
+-- A rejected mutation must raise provider_managed_subscription and change nothing.
+CREATE OR REPLACE FUNCTION pg_temp.expect_provider_guard(
+  p_label text,
+  p_tier text,
+  p_status text,
+  p_period_end timestamptz
+)
+RETURNS void
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  v_rejected boolean := false;
+  v_row public.subscriptions%ROWTYPE;
+BEGIN
+  BEGIN
+    PERFORM public.admin_mutate_subscription_v1(
+      'guard-manager@example.invalid', gen_random_uuid(), 'update',
+      '41900000-0000-4000-8000-000000000003',
+      p_tier, p_status, p_period_end, NULL, NULL, 'guard regression ' || p_label
+    );
+  EXCEPTION
+    WHEN check_violation THEN
+      PERFORM pg_temp.assert_true(
+        SQLERRM = 'provider_managed_subscription',
+        format('%s rejected with provider_managed_subscription, got %s', p_label, SQLERRM)
+      );
+      v_rejected := true;
+  END;
+  PERFORM pg_temp.assert_true(v_rejected, format('%s must be rejected on a Payple-owned row', p_label));
+
+  SELECT * INTO v_row FROM public.subscriptions
+   WHERE user_id = '41900000-0000-4000-8000-000000000003';
+  PERFORM pg_temp.assert_true(
+    v_row.tier = 'pro'
+      AND v_row.status = 'active'
+      AND v_row.provider = 'payple'
+      AND v_row.auto_renewing
+      AND v_row.current_period_end = '2026-10-15T03:12:45Z'::timestamptz,
+    format('%s left the Payple row unchanged: %s/%s/%s/%s', p_label,
+      v_row.tier, v_row.status, v_row.provider, v_row.current_period_end)
+  );
+END;
+$$;
+
+SELECT pg_temp.expect_provider_guard('manager tier comp', 'pro_plus', NULL, NULL);
+SELECT pg_temp.expect_provider_guard('manager tier downgrade', 'free', NULL, NULL);
+SELECT pg_temp.expect_provider_guard('manager status change', NULL, 'expired', NULL);
+SELECT pg_temp.expect_provider_guard('manager period shift', NULL, NULL, '2026-10-01T00:00:00Z');
+SELECT pg_temp.expect_provider_guard('form resend with new tier', 'pro_plus', 'active', '2026-10-15T00:00:00Z');
+
+-- The admin form resends tier/status and a day-granular period end on every
+-- save. Unchanged values must pass so notes and credits stay editable, and the
+-- stored period-end instant must not be truncated to midnight.
+DO $$
+DECLARE
+  v_result jsonb;
+  v_row public.subscriptions%ROWTYPE;
+BEGIN
+  v_result := public.admin_mutate_subscription_v1(
+    'guard-manager@example.invalid', gen_random_uuid(), 'update',
+    '41900000-0000-4000-8000-000000000003',
+    'pro', 'active', '2026-10-15T00:00:00Z', 250, 'support note', 'note-only edit'
+  );
+  PERFORM pg_temp.assert_true((v_result->>'success')::boolean, 'note-only edit succeeds');
+
+  SELECT * INTO v_row FROM public.subscriptions
+   WHERE user_id = '41900000-0000-4000-8000-000000000003';
+  PERFORM pg_temp.assert_true(
+    v_row.tier = 'pro'
+      AND v_row.provider = 'payple'
+      AND v_row.current_period_end = '2026-10-15T03:12:45Z'::timestamptz
+      AND v_row.overage_credits = 250
+      AND v_row.admin_note = 'support note',
+    format('note-only edit keeps billing terms: %s/%s/%s/%s/%s',
+      v_row.tier, v_row.provider, v_row.current_period_end, v_row.overage_credits, v_row.admin_note)
+  );
+END;
+$$;
+
+-- Admin-managed rows keep the existing manager edit behavior.
+DO $$
+DECLARE
+  v_row public.subscriptions%ROWTYPE;
+BEGIN
+  PERFORM public.admin_mutate_subscription_v1(
+    'guard-manager@example.invalid', gen_random_uuid(), 'update',
+    '41900000-0000-4000-8000-000000000004',
+    'pro_plus', 'active', '2026-12-01T00:00:00Z', NULL, NULL, 'comp grant'
+  );
+  SELECT * INTO v_row FROM public.subscriptions
+   WHERE user_id = '41900000-0000-4000-8000-000000000004';
+  PERFORM pg_temp.assert_true(
+    v_row.tier = 'pro_plus'
+      AND v_row.provider = 'none'
+      AND v_row.current_period_end = '2026-12-01T00:00:00Z'::timestamptz,
+    format('comp row accepts tier/period edits: %s/%s/%s', v_row.tier, v_row.provider, v_row.current_period_end)
+  );
+END;
+$$;
+
+-- Admin delete releases provider ownership: renewals stop and a new purchase is allowed.
+DO $$
+DECLARE
+  v_row public.subscriptions%ROWTYPE;
+BEGIN
+  PERFORM public.admin_mutate_subscription_v1(
+    'guard-admin@example.invalid', gen_random_uuid(), 'delete',
+    '41900000-0000-4000-8000-000000000003',
+    NULL, NULL, NULL, NULL, NULL, 'refund and revoke'
+  );
+  SELECT * INTO v_row FROM public.subscriptions
+   WHERE user_id = '41900000-0000-4000-8000-000000000003';
+  PERFORM pg_temp.assert_true(
+    v_row.tier = 'free'
+      AND v_row.status = 'expired'
+      AND v_row.provider = 'none'
+      AND v_row.payment_provider = 'none'
+      AND v_row.provider_resource_id IS NULL
+      AND v_row.auto_renewing IS FALSE,
+    format('delete releases provider ownership: %s/%s/%s/%s/%s/%s', v_row.tier, v_row.status,
+      v_row.provider, v_row.payment_provider, v_row.provider_resource_id, v_row.auto_renewing)
+  );
+  PERFORM pg_temp.assert_true(
+    (SELECT tier FROM public.profiles WHERE id = '41900000-0000-4000-8000-000000000003') = 'free',
+    'profile tier follows delete'
+  );
+END;
+$$;
+
+ROLLBACK;