Yorkshire Building Society

Yorkshire Building Society (YBS) is a UK mutual building society founded in 1864 and headquartered in Bradford, West Yorkshire. As a member-owned mutual rather than a shareholder-owned bank, it is owned by and run for the benefit of its savers and borrowers, with more than three million customers and around £66 billion in assets across the YBS Group, which trades under the Yorkshire Building Society, Chelsea Building Society (CBS), Norwich & Peterborough and Accord Mortgages brands. YBS is authorised by the Prudential Regulation Authority and regulated by the Financial Conduct Authority and the PRA as an FCA-authorised ASPSP. Although it is not one of the CMA9 banks mandated to build Open Banking, YBS is a voluntary participant in the UK Open Banking / PSD2 ecosystem and operates a public developer portal at developers.ybs.co.uk that documents its OBIE Read/Write API family - Account Information (AIS), Payment Initiation (PIS), Confirmation of Funds (CBPII), Event Subscriptions, Dynamic Client Registration, and token issuance - conformant to the Open Banking Implementation Entity (OBIE) Read/Write Data API Standard v3.1.2. Access to the production and sandbox surfaces (ob-ybs.api.ybs.co.uk / ob-che.api.ybs.co.uk and the matching sandbox hosts) is secured with FAPI-grade OAuth2/OIDC, PSD2 strong customer authentication, mutual-TLS transport authentication and PS256-signed JWTs, and is available to FCA-authorised third-party providers holding eIDAS/OBIE certificates.

Yorkshire Building Society publishes 4 APIs on the APIs.io network, including Account Information API, Payment Initiation API, Confirmation of Funds API, and 1 more. Tagged areas include Financial Services, Banking, Building Society, Open Banking, and PSD2.

The Yorkshire Building Society catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Yorkshire Building Society’s developer surface includes authentication, sandbox, documentation, getting-started guide, support, and 24 more developer resources.

🌐 Visit website 📡 Source on GitHub
47.4/100 developing ▬ flat Agent 84/100 agent native Full breakdown ↓
scored 2026-07-27 · rubric v0.5
6 APIs 1 MCP Servers
Financial ServicesBankingBuilding SocietyOpen BankingPSD2OBIEFAPIUnited KingdomPaymentsAccount InformationFintech

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 47.4/100 · developing
Contract Quality 14.0 / 25
Developer Ergonomics 13.0 / 20
Commercial Clarity 4.2 / 20
Operational Transparency 1.0 / 13
Governance 0.0 / 12
Discoverability 10.0 / 10
Agent readiness — 84/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 5 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 0 / 3
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/yorkshire-building-society: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 6

Individual APIs this provider publishes, each with its own machine-readable definition.

Yorkshire Building Society Account Information API

OBIE Read/Write Account and Transaction Information (AISP) API v3.1.2 - lets FCA-authorised account information service providers retrieve account, balance, transaction, benefic...

Yorkshire Building Society Payment Initiation API

OBIE Read/Write Payment Initiation (PISP) API v3.1.2 - lets FCA-authorised payment initiation service providers set up domestic single, scheduled, standing-order and file paymen...

Yorkshire Building Society Confirmation of Funds API

OBIE Read/Write Confirmation of Funds (CBPII) API v3.1.2 - lets FCA-authorised card-based payment instrument issuers set up a funds confirmation consent and confirm whether a sp...

Yorkshire Building Society Event Subscriptions API

OBIE Read/Write Event Subscriptions API v3.1.2 - lets an onboarded TPP create, read and delete event subscriptions so it can receive aggregated-polling and real-time event notif...

Yorkshire Building Society Dynamic Client Registration API

OBIE Dynamic Client Registration (DCR) API v3.1 - lets an FCA-authorised TPP present its OBIE/eIDAS software statement and register a client application with the YBS and Chelsea...

Yorkshire Building Society Generate Access Token API

OBIE token endpoint (Generate Access Token API v3.1.0) - the OAuth2/OIDC token endpoint used by onboarded TPPs to exchange authorization codes and client credentials for access ...

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

yorkshire-building-society-mcp.yml

MCP SERVER

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Yorkshire Building Society Events Webhooks

ASYNCAPI

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Yorkshire Building Society Authentication

oauth2/mutualTLS · 3 schemes

SECURITY

Yorkshire Building Society Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Yorkshire Building Society Scopes

4 scopes

4 scopes

SCOPES

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Yorkshire Building Society Agentic Access

78 operations · 23 acting

78 operations · 23 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

Sandbox
Sandbox
 DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess
 WellKnown
WellKnown
 MCPServer
MCPServer
 AgentSkill
AgentSkill
 LLMsTxt
LLMsTxt

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Conformance
Conformance
 ErrorCatalog
ErrorCatalog
 Lifecycle
Lifecycle
 Conventions
Conventions
 Idempotency
Idempotency
 DataModel
DataModel
 Webhooks
Webhooks

Scroll for all 7

Build 1

SDKs, sample code, and the tooling you integrate with

ToolCrosswalk
ToolCrosswalk

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 OAuthScopes
OAuthScopes
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

Support
Support

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy

Company 2

The organization behind the API

Website
Website
 LinkedIn
LinkedIn

Other 4

Properties that don't map to a standard resource type

Overlay
Overlay
 Overlay
Overlay
 Overlay
Overlay
 Overlay
Overlay

Source (apis.yml)

apis.yml Raw ↑ 
aid: yorkshire-building-society
url: https://raw.githubusercontent.com/api-evangelist/yorkshire-building-society/refs/heads/main/apis.yml
name: Yorkshire Building Society
kind: company
description: Yorkshire Building Society (YBS) is a UK mutual building society founded in 1864 and headquartered in Bradford,
  West Yorkshire. As a member-owned mutual rather than a shareholder-owned bank, it is owned by and run for the benefit of
  its savers and borrowers, with more than three million customers and around £66 billion in assets across the YBS Group,
  which trades under the Yorkshire Building Society, Chelsea Building Society (CBS), Norwich & Peterborough and Accord Mortgages
  brands. YBS is authorised by the Prudential Regulation Authority and regulated by the Financial Conduct Authority and the
  PRA as an FCA-authorised ASPSP. Although it is not one of the CMA9 banks mandated to build Open Banking, YBS is a voluntary
  participant in the UK Open Banking / PSD2 ecosystem and operates a public developer portal at developers.ybs.co.uk that
  documents its OBIE Read/Write API family - Account Information (AIS), Payment Initiation (PIS), Confirmation of Funds (CBPII),
  Event Subscriptions, Dynamic Client Registration, and token issuance - conformant to the Open Banking Implementation Entity
  (OBIE) Read/Write Data API Standard v3.1.2. Access to the production and sandbox surfaces (ob-ybs.api.ybs.co.uk / ob-che.api.ybs.co.uk
  and the matching sandbox hosts) is secured with FAPI-grade OAuth2/OIDC, PSD2 strong customer authentication, mutual-TLS
  transport authentication and PS256-signed JWTs, and is available to FCA-authorised third-party providers holding eIDAS/OBIE
  certificates.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Financial Services
- Banking
- Building Society
- Open Banking
- PSD2
- OBIE
- FAPI
- United Kingdom
- Payments
- Account Information
- Fintech
created: '2026-07-23'
modified: '2026-07-23'
specificationVersion: '0.19'
apis:
- aid: yorkshire-building-society:ybs-account-information-api
  name: Yorkshire Building Society Account Information API
  description: OBIE Read/Write Account and Transaction Information (AISP) API v3.1.2 - lets FCA-authorised account information
    service providers retrieve account, balance, transaction, beneficiary, standing order, direct debit, product, party and
    statement data for consenting YBS and Chelsea Building Society payment-account customers. FAPI-secured (OAuth2/OIDC, mTLS,
    PSD2 SCA).
  humanURL: https://developers.ybs.co.uk/api-catalog/account-information-api
  baseURL: https://ob-ybs.api.ybs.co.uk/open-banking/v3.1/aisp
  tags:
  - Account Information
  - AISP
  - Open Banking
  properties:
  - type: OpenAPI
    url: openapi/yorkshire-building-society-account-information-api-openapi.yaml
  - type: Documentation
    url: https://developers.ybs.co.uk/api-catalog/account-information-api
  - type: APIReference
    url: https://developers.ybs.co.uk/api-catalog/account-information-api
  - type: GettingStarted
    url: https://developers.ybs.co.uk/docs/getting-started
- aid: yorkshire-building-society:ybs-payment-initiation-api
  name: Yorkshire Building Society Payment Initiation API
  description: OBIE Read/Write Payment Initiation (PISP) API v3.1.2 - lets FCA-authorised payment initiation service providers
    set up domestic single, scheduled, standing-order and file payment consents and initiate payments from consenting YBS
    and Chelsea Building Society accounts. FAPI-secured (OAuth2/OIDC, mTLS, PSD2 SCA).
  humanURL: https://developers.ybs.co.uk/api-catalog/payment-initiation-api-0
  baseURL: https://ob-ybs.api.ybs.co.uk/open-banking/v3.1/pisp
  tags:
  - Payment Initiation
  - PISP
  - Payments
  properties:
  - type: OpenAPI
    url: openapi/yorkshire-building-society-payment-initiation-api-openapi.yaml
  - type: Documentation
    url: https://developers.ybs.co.uk/api-catalog/payment-initiation-api-0
  - type: APIReference
    url: https://developers.ybs.co.uk/api-catalog/payment-initiation-api-0
  - type: GettingStarted
    url: https://developers.ybs.co.uk/docs/getting-started
- aid: yorkshire-building-society:ybs-confirmation-of-funds-api
  name: Yorkshire Building Society Confirmation of Funds API
  description: OBIE Read/Write Confirmation of Funds (CBPII) API v3.1.2 - lets FCA-authorised card-based payment instrument
    issuers set up a funds confirmation consent and confirm whether a specified amount is available on a consenting YBS or
    Chelsea Building Society account. FAPI-secured (OAuth2/OIDC, mTLS, PSD2 SCA).
  humanURL: https://developers.ybs.co.uk/api-catalog/confirmation-funds-api
  baseURL: https://ob-ybs.api.ybs.co.uk/open-banking/v3.1/cbpii
  tags:
  - Confirmation of Funds
  - CBPII
  - Open Banking
  properties:
  - type: OpenAPI
    url: openapi/yorkshire-building-society-confirmation-of-funds-api-openapi.yaml
  - type: Documentation
    url: https://developers.ybs.co.uk/api-catalog/confirmation-funds-api
  - type: APIReference
    url: https://developers.ybs.co.uk/api-catalog/confirmation-funds-api
  - type: GettingStarted
    url: https://developers.ybs.co.uk/docs/getting-started
- aid: yorkshire-building-society:ybs-event-subscriptions-api
  name: Yorkshire Building Society Event Subscriptions API
  description: OBIE Read/Write Event Subscriptions API v3.1.2 - lets an onboarded TPP create, read and delete event subscriptions
    so it can receive aggregated-polling and real-time event notifications (for example consent revocation) for YBS and Chelsea
    Building Society Open Banking resources. FAPI-secured (OAuth2/OIDC, mTLS).
  humanURL: https://developers.ybs.co.uk/api-catalog/event-subscriptions-api
  baseURL: https://ob-ybs.api.ybs.co.uk/open-banking/v3.1/aisp
  tags:
  - Event Subscriptions
  - Notifications
  - Open Banking
  properties:
  - type: OpenAPI
    url: openapi/yorkshire-building-society-event-subscriptions-api-openapi.yaml
  - type: Documentation
    url: https://developers.ybs.co.uk/api-catalog/event-subscriptions-api
  - type: APIReference
    url: https://developers.ybs.co.uk/api-catalog/event-subscriptions-api
  - type: GettingStarted
    url: https://developers.ybs.co.uk/docs/getting-started
- aid: yorkshire-building-society:ybs-dynamic-client-registration-api
  name: Yorkshire Building Society Dynamic Client Registration API
  description: OBIE Dynamic Client Registration (DCR) API v3.1 - lets an FCA-authorised TPP present its OBIE/eIDAS software
    statement and register a client application with the YBS and Chelsea Building Society authorization servers. Part of the
    OBIE security profile; secured with mTLS and PS256-signed JWTs.
  humanURL: https://developers.ybs.co.uk/api-catalog/dynamic-client-registration-api-0
  baseURL: https://ob-ybs.api.ybs.co.uk/register
  tags:
  - Dynamic Client Registration
  - Security
  - OAuth
  properties:
  - type: Documentation
    url: https://developers.ybs.co.uk/api-catalog/dynamic-client-registration-api-0
  - type: APIReference
    url: https://developers.ybs.co.uk/api-catalog/dynamic-client-registration-api-0
  - type: GettingStarted
    url: https://developers.ybs.co.uk/docs/getting-started
- aid: yorkshire-building-society:ybs-generate-access-token-api
  name: Yorkshire Building Society Generate Access Token API
  description: OBIE token endpoint (Generate Access Token API v3.1.0) - the OAuth2/OIDC token endpoint used by onboarded TPPs
    to exchange authorization codes and client credentials for access tokens against the YBS and Chelsea Building Society
    authorization servers. FAPI-secured with mTLS and PS256-signed JWTs.
  humanURL: https://developers.ybs.co.uk/api-catalog/generate-access-token-api
  baseURL: https://ob-ybs.api.ybs.co.uk/token
  tags:
  - OAuth
  - Token
  - Security
  properties:
  - type: Documentation
    url: https://developers.ybs.co.uk/api-catalog/generate-access-token-api
  - type: APIReference
    url: https://developers.ybs.co.uk/api-catalog/generate-access-token-api
  - type: GettingStarted
    url: https://developers.ybs.co.uk/docs/getting-started
common:
- type: AgenticAccess
  url: agentic-access/yorkshire-building-society-agentic-access.yml
- type: DomainSecurity
  url: security/yorkshire-building-society-domain-security.yml
- type: OAuthScopes
  url: scopes/yorkshire-building-society-scopes.yml
- type: Authentication
  url: authentication/yorkshire-building-society-authentication.yml
- type: WellKnown
  url: well-known/yorkshire-building-society-well-known.yml
- type: Conformance
  url: conformance/yorkshire-building-society-conformance.yml
- type: ErrorCatalog
  url: errors/yorkshire-building-society-problem-types.yml
- type: Lifecycle
  url: lifecycle/yorkshire-building-society-lifecycle.yml
- type: Conventions
  url: conventions/yorkshire-building-society-conventions.yml
- type: Idempotency
  url: conventions/yorkshire-building-society-conventions.yml
- type: Sandbox
  url: sandbox/yorkshire-building-society-sandbox.yml
- type: DataModel
  url: data-model/yorkshire-building-society-data-model.yml
- type: Webhooks
  url: asyncapi/yorkshire-building-society-events-webhooks.yml
- type: MCPServer
  url: mcp/yorkshire-building-society-mcp.yml
- type: ToolCrosswalk
  url: mcp/yorkshire-building-society-tool-crosswalk.yml
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/yorkshire-building-society-llms.txt
- type: Overlay
  name: Account Information API overlay
  url: overlays/yorkshire-building-society-account-information-api-overlay.yaml
- type: Overlay
  name: Payment Initiation API overlay
  url: overlays/yorkshire-building-society-payment-initiation-api-overlay.yaml
- type: Overlay
  name: Confirmation of Funds API overlay
  url: overlays/yorkshire-building-society-confirmation-of-funds-api-overlay.yaml
- type: Overlay
  name: Event Subscriptions API overlay
  url: overlays/yorkshire-building-society-event-subscriptions-api-overlay.yaml
- type: Website
  url: https://www.ybs.co.uk/
- type: DeveloperPortal
  url: https://developers.ybs.co.uk/
- type: Documentation
  url: https://developers.ybs.co.uk/docs/getting-started
- type: GettingStarted
  url: https://developers.ybs.co.uk/docs/getting-started
- type: Support
  url: https://developers.ybs.co.uk/support
- type: TermsOfService
  url: https://developers.ybs.co.uk/legal
- type: PrivacyPolicy
  url: https://developers.ybs.co.uk/privacy-policy
- type: LinkedIn
  url: https://www.linkedin.com/company/yorkshire-building-society
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com