# Nationwide Building Society — Open Banking APIs

> Nationwide Building Society is the world's largest building society and one of the UK's biggest retail financial services providers. As one of the CMA9 it runs a public developer portal exposing UK Open Banking (OBIE) APIs: public, unauthenticated Open Data APIs (ATM/branch locators, product reference data) and FAPI-secured Read/Write APIs for Account Information (AIS), Payment Initiation (PIS), Confirmation of Funds (CBPII), and Variable Recurring Payments (VRP), secured with OAuth2/OIDC, mutual-TLS, and PSD2 strong customer authentication.

## Developer
- [Developer Portal](https://developer.nationwide.co.uk/): Nationwide Open Banking developer portal (Cloudflare bot-protected).
- [Open Banking Documentation](https://developer.nationwide.co.uk/open-banking): products, onboarding, roadmap.
- [Open Data APIs](https://developer.nationwide.co.uk/open-banking/open-data-apis): public unauthenticated reference APIs.
- [Support / FAQ](https://developer.nationwide.co.uk/open-banking/support/faq)
- [Known Issues / Status](https://developer.nationwide.co.uk/open-banking/support/known-issues)

## Open Data APIs (public, unauthenticated — base https://openapi.nationwide.co.uk/open-banking/v2.2)
- [ATM Locator](https://developer.nationwide.co.uk/open-banking/open-data-apis): GET /atms — ATM locations, accessibility, services. Confirmed live.
- [Branch Locator](https://developer.nationwide.co.uk/open-banking/open-data-apis): GET /branches — branch locations, opening times, services.
- [Personal Current Accounts](https://developer.nationwide.co.uk/open-banking/open-data-apis): GET /personal-current-accounts — product reference data. Confirmed live.

## Read/Write APIs (FAPI-secured, mTLS — base https://api.nationwide.co.uk/open-banking/v3.1)
- [Account & Transaction Information (AIS)](https://developer.nationwide.co.uk/open-banking/account-information-apis): scope `accounts`.
- [Payment Initiation (PIS)](https://developer.nationwide.co.uk/open-banking/payment-initiation-apis): scope `payments`.
- [Confirmation of Funds (CBPII)](https://developer.nationwide.co.uk/open-banking/utility-apis): scope `fundsconfirmations`.
- [Variable Recurring Payments (VRP)](https://developer.nationwide.co.uk/open-banking/payment-initiation-apis): scope `payments`, uplifting to v4.0.

## Specs & Artifacts
- OpenAPI (Open Data, Swagger 2.0): openapi/obie-open-data-atm-locator-openapi.json, openapi/obie-open-data-branch-locator-openapi.json, openapi/obie-open-data-personal-current-accounts-openapi.json
- Authentication: authentication/nationwide-building-society-authentication.yml
- OAuth scopes: scopes/nationwide-building-society-scopes.yml
- API conventions (idempotency, FAPI headers, pagination): conventions/nationwide-building-society-conventions.yml
- Error catalog (OBIE UK.OBIE.* codes): errors/nationwide-building-society-problem-types.yml
- Conformance (OBIE/FAPI/PSD2/OAuth2/OIDC/mTLS): conformance/nationwide-building-society-conformance.yml
- Lifecycle (v3.1 -> v4.0): lifecycle/nationwide-building-society-lifecycle.yml
- Data model: data-model/nationwide-building-society-data-model.yml

## Standard
- [OBIE Read/Write API Standard](https://openbankinguk.github.io/read-write-api-site3/)
- [OBIE Open Data specs](https://github.com/OpenBankingUK/opendata-api-docs-pub)

## Security
- [security.txt](https://www.nationwide.co.uk/.well-known/security.txt)
- [Report a security vulnerability](https://www.nationwide.co.uk/help/fraud-and-security/report-security-vulnerability)