generated: '2026-07-23'
method: searched
source: https://developer.nationwide.co.uk/open-banking
standard: OBIE Read/Write API Standard (FAPI 1.0 Advanced) + UK Open Banking Security Profile
docs: https://openbankinguk.github.io/read-write-api-site3/
summary:
  types: [none, oauth2, openIdConnect, mutualTLS]
  api_key_in: []
  oauth2_flows: [authorizationCode, clientCredentials]
  notes: >-
    Two distinct security tiers. The OBIE Open Data APIs (ATM/branch locators,
    product reference data) are fully public and unauthenticated. The Read/Write
    APIs (AIS/PIS/CBPII/VRP) require the full UK Open Banking FAPI security stack.
schemes:
- name: OpenData
  tier: open-data
  type: none
  applies_to:
  - Nationwide ATM Locator API
  - Nationwide Branch Locator API
  - Nationwide Personal Current Accounts API
  note: Public, unauthenticated OBIE Open Data. No token or key required.
- name: OAuth2
  tier: read-write
  type: oauth2
  scheme: FAPI 1.0 Advanced
  applies_to:
  - Nationwide Account and Transaction Information API (AIS)
  - Nationwide Payment Initiation API (PIS)
  - Nationwide Confirmation of Funds API (CBPII)
  - Nationwide Variable Recurring Payments API (VRP)
  flows:
  - flow: authorizationCode
    grant: authorization_code
    use: PSU consent authorisation (redirect + PSD2 SCA), used for AIS data access and payment authorisation
  - flow: clientCredentials
    grant: client_credentials
    use: TPP-only calls to create consent/intent resources before PSU authorisation
  scopes: [openid, accounts, payments, fundsconfirmations]
- name: OpenIDConnect
  tier: read-write
  type: openIdConnect
  note: >-
    OIDC hybrid flow with request object (JWT), id_token, and the OBIE `intent`
    claim (openbanking_intent_id) carrying the consent id. Enforces PSD2 Strong
    Customer Authentication.
- name: MutualTLS
  tier: read-write
  type: mutualTLS
  confirmed: true
  evidence: >-
    TLS handshake to api.nationwide.co.uk returns "Request CERT" then fails without
    a presented client certificate (probed 2026-07-23).
  note: >-
    OBIE/eIDAS transport certificates (OBWAC/OBSeal or QWAC/QSeal) required for
    mutual-TLS client authentication and message signing; TPPs onboard via the
    developer portal and dynamic client registration.
message_signing:
  header: x-jws-signature
  note: Detached JWS signature required on payment/consent write operations per the OBIE profile.