generated: '2026-07-23'
method: searched
source: https://developers.ybs.co.uk/docs/getting-started
note: >-
  YBS operates a dedicated OBIE sandbox that mirrors the production Read/Write
  surface for the YBS/CBS and Chelsea brands, plus an Authorisation Mock Page
  that stands in for PSU strong customer authentication so TPPs can complete the
  authorization-code flow without a real PSU. No published test-card or magic
  test-identifier catalogue was found; test data is provisioned per onboarded
  TPP. Values below are published verbatim on the developer portal.
environments:
  production:
    ybs_cbs_host: https://ob-ybs.api.ybs.co.uk
    chelsea_host: https://ob-che.api.ybs.co.uk
    dcr_register: https://ob-ybs.api.ybs.co.uk/open-banking/v3.1/tpp-client/register
    token_endpoint: https://ob-ybs.api.ybs.co.uk/identity/open-banking/v3.1/token
    openid_configuration: https://api.ybs.co.uk/open-banking/v1.0/.well-known/ybs/openid-configuration
  sandbox:
    ybs_cbs_host: https://ob-ybs.sandbox.ybs.co.uk
    chelsea_host: https://ob-che.sandbox.ybs.co.uk
    dcr_register: https://ob-ybs.sandbox.ybs.co.uk/open-banking/v3.1/tpp-client/register
    token_endpoint: https://ob-ybs.sandbox.ybs.co.uk/identity/open-banking/v3.1/token
    openid_configuration: https://sandbox.ybs.co.uk/open-banking/v1.0/.well-known/ybs/openid-configuration
test_tools:
- name: Authorisation Mock Page
  purpose: Simulates the PSU SCA/authorisation step so a TPP can obtain an authorization code and exchange it for an access token in the sandbox.
  location: YBS sandbox authorization flow.
onboarding:
  mechanism: Dynamic Client Registration (DCR) with an OBIE/eIDAS software statement.
  transport: Mutual-TLS with an OB/eIDAS transport certificate; PS256-signed request objects.
  note: TPPs must hold valid FCA authorisation and OBIE directory certificates to register.