diff --git a/src/agency/agency.service.spec.ts b/src/agency/agency.service.spec.ts
index 3cdec68..24892b8 100644
--- a/src/agency/agency.service.spec.ts
+++ b/src/agency/agency.service.spec.ts
@@ -55,6 +55,66 @@ describe('AgencyService', () => {
       data: { qcThreshold: 48, dockingTier: 'A', newNationalNotify: false },
     });
   });
+
+  it('无 agency 行时 PATCH 自动创建（最小默认值 + dto 字段，locCode 置空）', async () => {
+    const findUnique = vi.fn().mockResolvedValue(null);
+    const create = vi.fn().mockResolvedValue({ code: 'T001', orgName: '新机构' });
+    const update = vi.fn();
+    const prisma = { client: { agency: { findUnique, create, update } } };
+    const service = new AgencyService(prisma as unknown as PrismaService);
+
+    await runWithRequestContext(ctx, () =>
+      service.update({ orgName: '新机构', qcThreshold: 48, dockingTier: 'A', newNationalNotify: false }),
+    );
+
+    expect(create).toHaveBeenCalledWith({
+      data: {
+        code: 'T001',
+        orgName: '新机构',
+        orgType: '',
+        creditCode: '',
+        locCode: '',
+        locName: '',
+        svcSource: '',
+        address: '',
+        contactName: '',
+        contactPhone: '',
+        qcThreshold: 48,
+        dockingTier: 'A',
+        newNationalNotify: false,
+      },
+    });
+    expect(update).not.toHaveBeenCalled();
+  });
+
+  it('无 agency 行且 dto 为空时，create 落最小默认值（24/B/true）', async () => {
+    const findUnique = vi.fn().mockResolvedValue(null);
+    const create = vi.fn().mockResolvedValue({ code: 'T001' });
+    const update = vi.fn();
+    const prisma = { client: { agency: { findUnique, create, update } } };
+    const service = new AgencyService(prisma as unknown as PrismaService);
+
+    await runWithRequestContext(ctx, () => service.update({}));
+
+    expect(create).toHaveBeenCalledWith({
+      data: {
+        code: 'T001',
+        orgName: '',
+        orgType: '',
+        creditCode: '',
+        locCode: '',
+        locName: '',
+        svcSource: '',
+        address: '',
+        contactName: '',
+        contactPhone: '',
+        qcThreshold: 24,
+        dockingTier: 'B',
+        newNationalNotify: true,
+      },
+    });
+    expect(update).not.toHaveBeenCalled();
+  });
 });
 
 describe('UpdateAgencyDto.dockingTier', () => {
diff --git a/src/agency/agency.service.ts b/src/agency/agency.service.ts
index 338cf7d..0d3886b 100644
--- a/src/agency/agency.service.ts
+++ b/src/agency/agency.service.ts
@@ -1,10 +1,27 @@
-import { HttpStatus, Injectable } from '@nestjs/common';
+import { Injectable } from '@nestjs/common';
 import { PrismaService } from '../prisma/prisma.service.js';
 import { getRequestContext } from '../common/context/request-context.js';
-import { ErrorCodes } from '../common/error-codes.js';
-import { BusinessException } from '../common/business-exception.js';
 import { UpdateAgencyDto } from './dto.js';
 
+/** 无 agency 行时（R5：无 provisioning 路径）创建行的最小默认值。 */
+function agencyDefaults(code: string): Record<string, unknown> {
+  return {
+    code,
+    orgName: '',
+    orgType: '',
+    creditCode: '',
+    locCode: '',
+    locName: '',
+    svcSource: '',
+    address: '',
+    contactName: '',
+    contactPhone: '',
+    qcThreshold: 24,
+    dockingTier: 'B',
+    newNationalNotify: true,
+  };
+}
+
 /**
  * 机构（=租户）信息读写。Agency 是 TENANT_FREE 模型，主键 code = 当前租户 code，
  * 因此读写一律按 `ctx.tenantCode` 定位，而非 BaseCrudService 的 `findById(id)`。
@@ -19,13 +36,20 @@ export class AgencyService {
     return this.prisma.client.agency.findUnique({ where: { code: ctx.tenantCode } });
   }
 
-  /** 更新当前机构信息；写操作同样按 code = ctx.tenantCode 定位，禁止按 id。 */
+  /**
+   * 更新当前机构信息（upsert）；写操作同样按 code = ctx.tenantCode 定位，禁止按 id。
+   * R5：agency 无 provisioning 路径（空表 + 无 create），故无行时先建最小默认值行再落 dto 字段。
+   * 参保地 locCode/locName 只读，不随 PATCH 更新（建行时置空串，dto 不含这两字段）。
+   */
   async update(dto: UpdateAgencyDto) {
     const ctx = getRequestContext()!;
     const existing = await this.getCurrent();
     if (!existing) {
-      throw new BusinessException(ErrorCodes.ORG_NOT_FOUND, '机构不存在', HttpStatus.NOT_FOUND);
+      return this.prisma.client.agency.create({
+        data: { ...agencyDefaults(ctx.tenantCode), ...dto } as any,
+      });
     }
     return this.prisma.client.agency.update({ where: { code: ctx.tenantCode }, data: dto });
   }
 }
+