Principality Building Society

aid: principality-building-society
url: https://raw.githubusercontent.com/api-evangelist/principality-building-society/refs/heads/main/apis.yml
name: Principality Building Society
kind: company
description: Principality Building Society is the largest building society in Wales and the sixth largest in the United Kingdom,
  founded in 1860 and headquartered in Cardiff. It is a mutual, owned by and run for the benefit of its members rather than
  shareholders, holding total assets of more than £11 billion and operating around 71 branches and agencies alongside internet
  and telephone channels. Its product range is deliberately narrow - savings, residential mortgages and investments, plus
  a commercial lending division - and it does NOT offer current or payment accounts. Principality is authorised by the Prudential
  Regulation Authority and regulated by the Financial Conduct Authority and the PRA, and is a member of the Building Societies
  Association. It is NOT one of the nine CMA9 banks mandated to deliver UK Open Banking, and because it holds no payment accounts
  it falls outside the scope of the PSD2 / OBIE Read/Write (AIS, PIS, CBPII) standard. As of this profile Principality publishes
  no public developer portal and no confirmed OBIE Open Data API endpoint; the Open Banking API family below is represented
  as the shared Open Banking Implementation Entity (OBIE) standard for reference only, not as a Principality-operated contract.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Financial Services
- Banking
- Building Society
- Savings
- Mortgages
- Open Banking
- Open Data
- PSD2
- OBIE
- United Kingdom
- Wales
- Mutual
created: '2026-07-23'
modified: '2026-07-23'
specificationVersion: '0.19'
apis:
- aid: principality-building-society:obie-open-data-api
  name: OBIE Open Data API (Shared Standard - Unverified for Principality)
  description: The UK Open Banking Implementation Entity (OBIE) Open Data API standard - public, unauthenticated reference
    data covering Branches, ATMs, Personal Current Accounts, Business Current Accounts, Unsecured SME Loans and Commercial
    Credit Cards. This entry represents the SHARED OBIE standard (Open Data API v1.3); no live Principality Open Data host
    was confirmed (probes to developer.principality.co.uk and api.principality.co.uk failed to resolve, and /open-banking
    returned 404). Principality is not a CMA9 bank and is not known to publish these endpoints. The harvested OpenAPI is the
    OBIE standard, not a Principality contract.
  humanURL: https://openbankinguk.github.io/opendata-api-docs-pub/v2.4.0/
  properties:
  - type: OpenAPI
    url: openapi/obie-open-data-swagger.json
  - type: Documentation
    url: https://openbankinguk.github.io/knowledge-base-pub/standards/open-data.html
  - type: APIReference
    url: https://openbankinguk.github.io/opendata-api-docs-pub/v2.4.0/
  - type: SourceCode
    url: https://github.com/OpenBankingUK/opendata-api-spec-compiled
  tags:
  - Open Data
  - Branches
  - ATMs
  - Reference Data
- aid: principality-building-society:obie-account-transaction-api
  name: OBIE Account & Transaction Information API (AIS - Standard, Out of Scope)
  description: The OBIE Read/Write Account and Transaction Information (AISP) standard for reading account, balance and transaction
    data. FAPI-secured with OAuth2/OIDC, mutual-TLS and PSD2 strong customer authentication. Represented here as the documented
    OBIE standard only - Principality offers no current or payment accounts, publishes no ASPSP developer portal, and is therefore
    OUTSIDE the scope of this Read/Write API. No Principality base URL or credentials exist; none are invented.
  humanURL: https://github.com/OpenBankingUK/read-write-api-specs
  properties:
  - type: Documentation
    url: https://github.com/OpenBankingUK/read-write-api-specs
  - type: APIReference
    url: https://openbankinguk.github.io/read-write-api-site3/
  tags:
  - Account Information
  - AIS
  - PSD2
  - FAPI
- aid: principality-building-society:obie-payment-initiation-api
  name: OBIE Payment Initiation API (PIS - Standard, Out of Scope)
  description: The OBIE Read/Write Payment Initiation (PISP) standard for initiating domestic, scheduled, standing-order,
    international and file payments. FAPI-secured with OAuth2/OIDC, mutual-TLS and PSD2 strong customer authentication. Represented
    as the documented OBIE standard only - Principality holds no payment accounts and operates no PISP endpoint, so this is
    out of scope. No Principality host is fabricated.
  humanURL: https://github.com/OpenBankingUK/read-write-api-specs
  properties:
  - type: Documentation
    url: https://github.com/OpenBankingUK/read-write-api-specs
  - type: APIReference
    url: https://openbankinguk.github.io/read-write-api-site3/
  tags:
  - Payment Initiation
  - PIS
  - PSD2
  - FAPI
- aid: principality-building-society:obie-confirmation-of-funds-api
  name: OBIE Confirmation of Funds API (CBPII - Standard, Out of Scope)
  description: The OBIE Read/Write Confirmation of Funds (CBPII) standard for confirming whether funds are available on a
    payment account. FAPI-secured with OAuth2/OIDC, mutual-TLS and PSD2 strong customer authentication. Represented as the
    documented OBIE standard only - Principality offers no payment accounts and provides no CBPII endpoint. No Principality
    host is invented.
  humanURL: https://github.com/OpenBankingUK/read-write-api-specs
  properties:
  - type: Documentation
    url: https://github.com/OpenBankingUK/read-write-api-specs
  - type: APIReference
    url: https://openbankinguk.github.io/read-write-api-site3/
  tags:
  - Confirmation of Funds
  - CBPII
  - PSD2
  - FAPI
common:
- type: DomainSecurity
  url: security/principality-building-society-domain-security.yml
- type: Authentication
  url: authentication/principality-building-society-authentication.yml
- type: Conformance
  url: conformance/principality-building-society-conformance.yml
- type: ErrorCatalog
  url: errors/principality-building-society-problem-types.yml
- type: LLMsTxt
  url: llms/principality-building-society-llms.txt
- type: Website
  url: https://www.principality.co.uk/
- type: About
  url: https://www.principality.co.uk/home/about-us
- type: News
  url: https://www.principality.co.uk/home/about-us/principality-news
- type: Support
  url: https://www.principality.co.uk/home/contact-us/help-and-support
- type: TermsOfService
  url: https://www.principality.co.uk/home/terms-of-use
- type: PrivacyPolicy
  url: https://www.principality.co.uk/home/terms-of-use/privacy-and-security
- type: LinkedIn
  url: https://www.linkedin.com/company/principality-building-society/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com