# Nationwide Building Society

**Canonical:** https://apis.io/providers/nationwide-building-society/  
**Website:** https://www.nationwide.co.uk/  
**APIs profiled:** 7

Nationwide Building Society is the world's largest building society and one of the UK's biggest retail financial services providers, headquartered in Swindon, England. As a mutual it is owned by and run for the benefit of its members rather than external shareholders, offering current accounts, mortgages, savings, and personal loans across a large branch and digital network. Nationwide is authorised by the Prudential Regulation Authority and regulated by the Financial Conduct Authority and the PRA. As one of the CMA9 - the nine largest current-account providers mandated by the UK Competition and Markets Authority to deliver Open Banking - Nationwide operates a public developer portal that publishes UK Open Banking APIs conformant to the Open Banking Implementation Entity (OBIE) standards - public, unauthenticated Open Data APIs (ATM and branch locators, personal and business current account product reference data) and FAPI-secured Read/Write APIs for Account and Transaction Information (AIS), Payment Initiation (PIS), Confirmation of Funds (CBPII), and Variable Recurring Payments (VRP), secured with OAuth2/OIDC, mutual-TLS client authentication, and PSD2 strong customer authentication using OBIE/eIDAS certificates.

## Kin Score — 45.6 / 100 (developing)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 45.6).

| Facet | Score |
|---|---|
| Discoverability | 92.6 |
| Contract Quality | 38.0 |
| Governance | 30.3 |
| Contract Governance | 30.3 |
| Operational Transparency | 39.5 |
| Developer Ergonomics | 49.4 |
| Commercial Clarity | 13.2 |
| Access Clarity | 13.2 |

Regulatory layer — **Banking & Open Finance**: 68.4 (matched via tags).

## Agent readiness — 40.6 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | no |
| Reversibility Documented | na |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | na |
| Error Semantics | documented |
| OpenAPI Examples | partial |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | derived |
| Well Known Catalog | no |
| Consent Identity | yes |
| Agent Card | no |
| Dry Run Mode | na |

## Access

Self-serve signup — onboarding: self-serve, pricing: unknown, trial: no (confidence: medium).

## APIs (7)

- **Nationwide ATM Locator API** — Public, unauthenticated OBIE Open Data API listing the location, accessibility, supported currencies, and services of Nationwide ATMs across the UK. Confirmed live (HTTP 200, ap...
- **Nationwide Branch Locator API** — Public, unauthenticated OBIE Open Data API listing Nationwide branch locations, opening hours, accessibility, and services. Documented Open Data type on the developer portal (th...
- **Nationwide Personal Current Accounts API** — Public, unauthenticated OBIE Open Data API publishing reference data for Nationwide personal current account products, features, fees, and eligibility. Confirmed live (HTTP 200,...
- **Nationwide Account and Transaction Information API (AIS)** — OBIE Read/Write Account and Transaction Information (AIS) API providing consented access to Nationwide account, balance, and transaction data for authorised third-party provider...
- **Nationwide Payment Initiation API (PIS)** — OBIE Read/Write Payment Initiation (PIS) API allowing authorised third-party providers to initiate domestic and other payments from Nationwide accounts with customer consent. FA...
- **Nationwide Confirmation of Funds API (CBPII)** — OBIE Read/Write Confirmation of Funds (CBPII) utility API letting a consented card-based payment instrument issuer check whether funds are available on a Nationwide account. FAP...
- **Nationwide Variable Recurring Payments API (VRP)** — OBIE Read/Write Variable Recurring Payments (VRP) API enabling consented sweeping and recurring payment mandates from Nationwide accounts. FAPI-secured (OAuth2/OIDC, mutual-TLS,...

## MCP servers (1)

- **Nationwide Building Society MCP Server**

## Security (3)

- **Nationwide Building Society Authentication** — none/oauth2/openIdConnect/mutualTLS · 4 schemes
- **Nationwide Building Society Domain Security** — TLSv1.3 · HSTS · DMARC
- **Nationwide Building Society Vulnerability Disclosure** — security.txt · contact published

## Tags

Financial-Services, Banking, Building Society, Open Banking, PSD2, OBIE, CMA9, United Kingdom, Payments, Account Information

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/nationwide-building-society/). Scores are computed from the provider's own public artifacts under a published rubric.