GB Bank

GB Bank Limited is a UK challenger bank headquartered in Middlesbrough (2 Centre Square) with a London office (73 Brook Street, Mayfair). Wholly owned and privately backed rather than a mutual building society, it secured its full UK banking licence in 2022 and is authorised by the Prudential Regulation Authority and regulated by the Financial Conduct Authority and the PRA (Financial Services Register number 850286). GB Bank funds SME regional property developers and investors with development finance, buy-to-let and bridging loans (typically between £26k and £5m across underserved UK regions) and funds that lending with retail deposits - fixed-rate bonds, notice accounts and easy-access savings accounts protected by the FSCS up to £85,000, managed through an online portal and a GB Bank mobile app. As a small, non-CMA9 FCA-authorised bank focused on savings and secured lending, GB Bank does not operate a public developer portal or a documented UK Open Banking (OBIE / PSD2) API surface; the Open Banking API families listed here are represented as the shared industry standard the bank would conform to as an FCA-authorised ASPSP, and are unverified for GB Bank pending a confirmed developer portal or Open Data endpoint.

GB Bank publishes 4 APIs on the APIs.io network, including Account and Transaction Information API (AIS), Payment Initiation API (PIS), Confirmation of Funds API (CBPII), and 1 more. Tagged areas include Financial-Services, Banking, Open Banking, PSD2, and OBIE.

GB Bank’s developer surface includes authentication, support, engineering blog, and 17 more developer resources.

🌐 Visit website 📡 Source on GitHub

36.1/100 thin ▬ flat Agent 39/100 agent ready Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0

4 APIs

Financial-ServicesBankingOpen BankingPSD2OBIEUnited KingdomPaymentsAccount InformationSavingsProperty FinanceSME LendingFintech

Kin Score

Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0

Composite quality — 36.1/100 · thin

Contract Quality 10.9 / 21

Developer Ergonomics 3.2 / 17

Access Clarity 3.6 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.5 / 10

Discoverability 6.1 / 9

Regulatory Posture 12.2 / 15

Agent readiness — 39/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Regulatory Posture applies to this provider. Its tags matched the Banking & Open Finance regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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/gb-bank: 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 4

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

Scopes 1

OAuth scopes governing access to this provider's APIs.

Gb Bank Scopes

3 scopes · clientCredentials/authorizationCode

3 scopes

SCOPES

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions

Idempotency

ErrorCatalog

Conformance

DataModel

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 3

The organization behind the API

Website

Website

Blog

Blog

LinkedIn

Other 4

Properties that don't map to a standard resource type

Savings

MobileApp

Standard

Standard

Source (apis.yml)

aid: gb-bank
url: https://raw.githubusercontent.com/api-evangelist/gb-bank/refs/heads/main/apis.yml
name: GB Bank
kind: company
description: GB Bank Limited is a UK challenger bank headquartered in Middlesbrough (2 Centre Square) with a London office
  (73 Brook Street, Mayfair). Wholly owned and privately backed rather than a mutual building society, it secured its full
  UK banking licence in 2022 and is authorised by the Prudential Regulation Authority and regulated by the Financial Conduct
  Authority and the PRA (Financial Services Register number 850286). GB Bank funds SME regional property developers and investors
  with development finance, buy-to-let and bridging loans (typically between £26k and £5m across underserved UK regions) and
  funds that lending with retail deposits - fixed-rate bonds, notice accounts and easy-access savings accounts protected by
  the FSCS up to £85,000, managed through an online portal and a GB Bank mobile app. As a small, non-CMA9 FCA-authorised bank
  focused on savings and secured lending, GB Bank does not operate a public developer portal or a documented UK Open Banking
  (OBIE / PSD2) API surface; the Open Banking API families listed here are represented as the shared industry standard the
  bank would conform to as an FCA-authorised ASPSP, and are unverified for GB Bank pending a confirmed developer portal or
  Open Data endpoint.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Financial-Services
- Banking
- Open Banking
- PSD2
- OBIE
- United Kingdom
- Payments
- Account Information
- Savings
- Property Finance
- SME Lending
- Fintech
tags_raw:
- Financial Services
- Banking
- Open Banking
- PSD2
- OBIE
- United Kingdom
- Payments
- Account Information
- Savings
- Property Finance
- SME Lending
- Fintech
created: '2026-07-23'
modified: '2026-07-23'
specificationVersion: '0.23'
apis:
- aid: gb-bank:gb-bank-account-transaction-information-api
  name: GB Bank Account and Transaction Information API (AIS)
  description: UK Open Banking Read/Write Account & Transaction Information API (AISP) - the OBIE standard for accessing account,
    balance, transaction and statement data with customer consent. FAPI-secured (OAuth2/OIDC, mTLS, PSD2 SCA). Represented
    here as the shared OBIE Read/Write Standard; UNVERIFIED for GB Bank - no GB Bank developer portal or production/sandbox
    base URL was found (no fabricated host).
  humanURL: https://github.com/OpenBankingUK/read-write-api-specs
  baseURL: ''
  tags:
  - Account Information
  - Transaction
  - AISP
  - FAPI
  tags_raw:
  - Account Information
  - Transactions
  - AISP
  - FAPI
  properties:
  - type: OpenAPI
    url: openapi/uk-open-banking-account-info-api-openapi.yaml
  - type: Documentation
    url: https://standards.openbanking.org.uk/
  - type: APIReference
    url: https://github.com/OpenBankingUK/read-write-api-specs
- aid: gb-bank:gb-bank-payment-initiation-api
  name: GB Bank Payment Initiation API (PIS)
  description: UK Open Banking Read/Write Payment Initiation API (PISP) - the OBIE standard for initiating domestic, scheduled,
    standing-order, international and file payments with customer consent. FAPI-secured (OAuth2/OIDC, mTLS, PSD2 SCA). Represented
    here as the shared OBIE Read/Write Standard; UNVERIFIED for GB Bank - no GB Bank developer portal or base URL was confirmed
    (no fabricated host).
  humanURL: https://github.com/OpenBankingUK/read-write-api-specs
  baseURL: ''
  tags:
  - Payment Initiation
  - Payments
  - PISP
  - FAPI
  properties:
  - type: OpenAPI
    url: openapi/uk-open-banking-payment-initiation-api-openapi.yaml
  - type: Documentation
    url: https://standards.openbanking.org.uk/
  - type: APIReference
    url: https://github.com/OpenBankingUK/read-write-api-specs
- aid: gb-bank:gb-bank-confirmation-of-funds-api
  name: GB Bank Confirmation of Funds API (CBPII)
  description: UK Open Banking Read/Write Confirmation of Funds API (CBPII) - the OBIE standard for confirming whether funds
    are available on a payment account with customer consent. FAPI-secured (OAuth2/OIDC, mTLS, PSD2 SCA). Represented here
    as the shared OBIE Read/Write Standard; UNVERIFIED for GB Bank - no GB Bank developer portal or base URL was confirmed
    (no fabricated host).
  humanURL: https://github.com/OpenBankingUK/read-write-api-specs
  baseURL: ''
  tags:
  - Confirmation of Funds
  - CBPII
  - FAPI
  properties:
  - type: OpenAPI
    url: openapi/uk-open-banking-confirmation-of-funds-api-openapi.yaml
  - type: Documentation
    url: https://standards.openbanking.org.uk/
  - type: APIReference
    url: https://github.com/OpenBankingUK/read-write-api-specs
- aid: gb-bank:uk-open-banking-open-data-api-openapi
  name: GB Bank Open Data API
  description: GB Bank Open Data API from GB Bank — 6 path(s) described in OpenAPI.
  humanURL: https://github.com/OpenBankingUK/read-write-api-specs
  properties:
  - type: OpenAPI
    url: openapi/uk-open-banking-open-data-api-openapi.json
common:
- type: DomainSecurity
  url: security/gb-bank-domain-security.yml
- type: AgenticAccess
  url: agentic-access/gb-bank-agentic-access.yml
- type: OAuthScopes
  url: scopes/gb-bank-scopes.yml
- type: Authentication
  url: authentication/gb-bank-authentication.yml
- type: Conventions
  url: conventions/gb-bank-conventions.yml
- type: Idempotency
  url: conventions/gb-bank-conventions.yml
- type: ErrorCatalog
  url: errors/gb-bank-problem-types.yml
- type: Conformance
  url: conformance/gb-bank-conformance.yml
- type: DataModel
  url: data-model/gb-bank-data-model.yml
- type: LLMsTxt
  url: llms/gb-bank-llms.txt
- type: Website
  url: https://www.gbbank.co.uk/
- type: Savings
  url: https://www.gbbank.co.uk/savings
- type: MobileApp
  url: https://www.gbbank.co.uk/gb-bank-mobile-app
- type: Support
  url: https://www.gbbank.co.uk/help-and-support/faqs
- type: Blog
  url: https://www.gbbank.co.uk/news
- type: TermsOfService
  url: https://www.gbbank.co.uk/terms
- type: PrivacyPolicy
  url: https://www.gbbank.co.uk/privacy-policy
- type: LinkedIn
  url: https://www.linkedin.com/company/thegbb
- type: Standard
  name: UK Open Banking Open Data Standard
  url: https://github.com/OpenBankingUK/opendata-api-spec-compiled
- type: Standard
  name: UK Open Banking Read/Write API Standard
  url: https://standards.openbanking.org.uk/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

GB Bank

Kin Score

APIs 4

GB Bank Account and Transaction Information API (AIS)

GB Bank Payment Initiation API (PIS)

GB Bank Confirmation of Funds API (CBPII)

GB Bank Open Data API

Open Collections 1

Open Data API

Security Posture 2

Gb Bank Authentication

Gb Bank Domain Security