> ## Documentation Index > Fetch the complete documentation index at: https://docs.fastcac.com/llms.txt > Use this file to discover all available pages before exploring further. # Look up a NIN > What NIMC holds for a NIN: names, gender, date of birth, phone, address, photo and its other fields. Prefill your form from it, set it as a proprietor's `nin_lookup`, and use its photo as the passport. Charged from your wallet (see `amount_charged`); not when NIMC has no record. ## OpenAPI ````yaml /openapi.json post /identities/nin_lookups openapi: 3.1.0 info: title: FastCAC API description: Register Nigerian businesses with CAC from your own product. version: '2026-11-01' servers: - url: https://api.fastcac.com/v1 security: - apiKey: [] tags: - name: Account description: Check your key and see your organization. - name: Names description: >- Check a business name against CAC's rules and registry, and the categories it takes, before registering it. - name: Registrations description: Register a Business Name with CAC, from draft to certificate. - name: Identities description: >- Look up a proprietor's NIN with NIMC, to prefill a registration and use their photo. - name: Balance description: >- Your prepaid wallet: what's available, its transactions and your funding account. - name: Test helpers description: >- Test keys only: move a registration on without waiting, or simulate a deposit. - name: Webhooks description: Endpoints that receive events, and the events sent to them. - name: Webhook events description: What FastCAC POSTs to your webhook endpoints. paths: /identities/nin_lookups: post: tags: - Identities summary: Look up a NIN description: >- What NIMC holds for a NIN: names, gender, date of birth, phone, address, photo and its other fields. Prefill your form from it, set it as a proprietor's `nin_lookup`, and use its photo as the passport. Charged from your wallet (see `amount_charged`); not when NIMC has no record. operationId: create_nin_lookup_identities_nin_lookups_post parameters: - name: simulate in: query required: false schema: anyOf: - type: string - type: 'null' description: >- Test keys only: nin_not_found (422) or insufficient_balance (402). Ignored with a live key. title: Simulate description: >- Test keys only: nin_not_found (422) or insufficient_balance (402). Ignored with a live key. requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/NinLookupIn' example: nin: '12345678901' consent: true responses: '201': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/V1NinLookup' examples: Example: value: object: nin_lookup id: ninl_6x9CKdEGQkJAbby8D1u7kN nin: '12345678901' first_name: ADA middle_name: CHIOMA last_name: OBI gender: female date_of_birth: '1990-04-12' phone: '08031234567' address: 12 ADMIRALTY WAY, LEKKI, LAGOS photo: data:image/jpeg;base64,/9j/4AAQSkZJRgABA… nimc_data: {} amount_charged: '100.00' transaction_id: wtx_0hA6wRH6yeYHTLfRjK4Bxn created_at: '2026-10-26T05:55:58Z' '400': description: The request is invalid; `param` names the field. content: application/json: schema: $ref: '#/components/schemas/Error' examples: Example: value: error: type: invalid_request_error code: consent_required message: >- Set consent to true to confirm the person whose NIN this is agreed to the lookup. param: consent request_id: req_xcacu6qO33kUNHSxBjY5G9Yd '401': description: The API key is missing, malformed, revoked or expired. content: application/json: schema: $ref: '#/components/schemas/Error' examples: Example: value: error: type: authentication_error code: api_key_missing message: 'Send your API key as `Authorization: Bearer `.' param: null request_id: req_hXO9uf6JYXxTYMz20Du2lF8n '402': description: >- The wallet can't cover a lookup: `insufficient_balance`, with `details`. Nothing was charged or looked up. content: application/json: schema: $ref: '#/components/schemas/V1Error' examples: Example: value: error: type: payment_error code: insufficient_balance message: >- Your balance is ₦0.00; a NIN lookup costs ₦100.00. Fund your wallet by bank transfer to your funding account, then try again. param: null request_id: req_T3QuXz9S4mAUr6Ilj7UfFnD3 details: amount_due: '100.00' balance: '0.00' currency: NGN funding_account: account_number: '0000000000' bank_name: TEST BANK account_name: FastCAC - TEST MODE '403': description: >- The key can't do this (for example, a test helper called with a live key). content: application/json: schema: $ref: '#/components/schemas/Error' examples: Example: value: error: type: permission_error code: live_mode_unavailable message: >- Live registrations are paused right now. Use a test key (fc_test_…) meanwhile. param: null request_id: req_gXc3KKfa1egcBqGIxApcVRIr '404': description: No such object for this key's organization and mode. content: application/json: schema: $ref: '#/components/schemas/Error' examples: Example: value: error: type: not_found_error code: resource_missing message: 'No such registration: reg_0000000000000000000000.' param: id request_id: req_5pBegFvIypCQp0ZmlXajiiet '409': description: >- The object's state doesn't allow this, or the Idempotency-Key was reused. content: application/json: schema: $ref: '#/components/schemas/Error' '422': description: '`nin_not_found`: NIMC has no record of the NIN. Not charged.' content: application/json: schema: $ref: '#/components/schemas/V1Error' examples: Example: value: error: type: invalid_request_error code: nin_not_found message: >- NIMC has no record of that NIN. Check the number. You weren't charged. param: nin request_id: req_SBKLBRia3TtzbQESMsQ1vznD '429': description: Too many requests; wait for `Retry-After` seconds. content: application/json: schema: $ref: '#/components/schemas/Error' '503': description: >- `nin_lookup_unavailable`: the identity service didn't answer. Not charged. content: application/json: schema: $ref: '#/components/schemas/V1Error' components: schemas: NinLookupIn: properties: nin: type: string title: Nin description: The person's National Identification Number, 11 digits. consent: type: boolean title: Consent description: 'Must be true: you confirm the person agreed to this lookup.' type: object required: - nin - consent title: NinLookupIn V1NinLookup: properties: object: type: string const: nin_lookup title: Object default: nin_lookup id: type: string title: Id description: >- ninl_…: pass it as a proprietor's `nin_lookup`, or to use the photo as the passport. nin: type: string title: Nin first_name: anyOf: - type: string - type: 'null' title: First Name description: As NIMC holds it (usually upper case). middle_name: anyOf: - type: string - type: 'null' title: Middle Name description: Goes in the proprietor's `other_names`. last_name: anyOf: - type: string - type: 'null' title: Last Name gender: anyOf: - type: string enum: - male - female - type: 'null' title: Gender date_of_birth: anyOf: - type: string - type: 'null' title: Date Of Birth description: YYYY-MM-DD. phone: anyOf: - type: string - type: 'null' title: Phone address: anyOf: - type: string - type: 'null' title: Address description: >- NIMC's residence address as one line; the registration takes it in parts. photo: anyOf: - type: string - type: 'null' title: Photo description: 'NIMC''s photo as a data: URI (JPEG).' nimc_data: additionalProperties: true type: object title: Nimc Data description: Every other field NIMC returned, as it came. amount_charged: anyOf: - type: string - type: 'null' title: Amount Charged description: What the lookup cost, in naira, as a decimal string. transaction_id: anyOf: - type: string - type: 'null' title: Transaction Id description: The wtx_… nin_lookup_charge. created_at: anyOf: - type: string - type: 'null' title: Created At type: object required: - id - nin - first_name - middle_name - last_name - gender - date_of_birth - phone - address - photo - nimc_data - amount_charged - transaction_id - created_at title: V1NinLookup Error: properties: error: $ref: '#/components/schemas/ErrorDetail' required: - error title: V1Error type: object V1Error: properties: error: $ref: '#/components/schemas/ErrorDetail' required: - error title: V1Error type: object ErrorDetail: properties: type: type: string enum: - invalid_request_error - authentication_error - payment_error - permission_error - not_found_error - idempotency_error - rate_limit_error - api_error title: Type code: type: string title: Code description: Stable and machine-readable, e.g. registration_incomplete. message: type: string title: Message description: For a developer to read; may change. param: anyOf: - type: string - type: 'null' title: Param description: The parameter at fault, as a path like proprietors[0].nin. request_id: anyOf: - type: string - type: 'null' title: Request Id description: Also in the FastCAC-Request-Id header. Quote it to support. details: anyOf: - additionalProperties: true type: object - type: 'null' title: Details description: >- Only on some errors. A 402 insufficient_balance carries amount_due, balance, currency and funding_account (number, bank, name; null until it's active). type: object required: - type - code - message - param - request_id title: ErrorDetail securitySchemes: apiKey: type: http scheme: bearer description: 'Your secret API key: fc_test_… in test mode, fc_live_… in live mode.' ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.