Nationwide Building Society
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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Nationwide Building Society the way a machine reads it — 14 machine-readable artifacts across 3 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Nationwide Building Society scores 41.9/100 (developing), with a separate agent-readiness read of 25/100 (agent aware). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-08 · rubric v0.20.0
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title="Nationwide Building Society on API Evangelist — API profile and Kin Score">
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title="Nationwide Building Society on API Evangelist — API profile and Kin Score">
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alt="Nationwide Building Society Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile Nationwide Building Society
Each block below is one kind of artifact we hold for Nationwide Building Society. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 7
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
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,...
Nationwide Building Society ATM API
Endpoint for getting ATM data
Nationwide Building Society Branch API
Endpoint for getting Branch data
Nationwide Building Society PCA API
Endpoint for getting Personal Current Account data
Scroll within the panel for all 7 ·
Open Collections 3
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Security Posture 3
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes are the vocabulary of least-privilege access. Profiling them shows exactly what an integration — or an agent acting on a user's behalf — is allowed to do.
OAuth scopes governing access to this provider's APIs.
Resources
Every other property we hold for Nationwide Building Society — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 3
Portal, sign-up, and the first successful call
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 4
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 6
Pagination, idempotency, versioning, errors, and events
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 6
Authentication, authorization, and security posture
Operate 4
Status, limits, changes, and where to get help
Company 3
The organization behind the API
Other 4
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/nationwide-building-society · machine-readable index on apis.io
This is an independent, third-party profile of Nationwide Building Society, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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