The YBSG API Developer Portal is where developers can learn about APIs for YBS services and customers. Third Party Providers (TPPs) will need to be authorised by the FCA and registered with Open Banking before they access the Open Banking APIs. Follow our Getting Started Guide to learn more.

No, this site and the APIs are designed for third parties to build new connected experiences which you as a customer can enjoy. Accessing and managing your account can be done via our web sites and

YBSG API documentation is available via the Developer Portal API Link.

TPPs who have registered and been certified Open Banking will be able to access our Test Interface and test new apps and experiences against stub dataset.

Follow our Getting Started Guide to learn more.

YBSG API documentation and its availability can be found via the Developer Portal API link.

Yes, when you make an API call you will need to specify which brand the account is from. 
When building services for YBSG customers you should provide the capability to select either the YBS or Chelsea brand before initiating the authorisation for account access.

Currently YBS and Chelsea accounts are available access via API.

No, a single registration at YBSG (Group level) will allow access to YBS and Chelsea Building Society customer information.

Payment Accounts from the Yorkshire Building Society (YBS) and Chelsea Building Society (CBS) are accessible via APIs in accordance with PSD2 regulation. Non-payment accounts in those brands, as well as mortgage account information, are not available at this time.

From the 25th May 2018 you will need to ensure compliance with the General Data Protection Regulation (GDPR).

The data you access and the nature of your business will dictate what you need to do to ensure the safety of customer’s data, unfortunately YBS cannot advise you on the specifics of your business.

For more details on data protection in the EU refer to the European Commission’s advice on data protection or for UK specific advice, refer to the ICO.


Maintaining good cyber security is essential in order to protect customers and their data. We recommend maintaining good technical controls, keeping abreast of good security practices such as the OWASP top 10 critical security risks and the international security standards.

In-line with payments made on the YBS and Chelsea websites, payments to another person or merchant will normally reach the destination by the end of the following day.

YBSG’s online banking service is available 23 hours a day – unavailable 03:00 – 04:00.

We monitor the performance and availability of our APIs as well as the performance and availability of our own customer interfaces.

Statistics on the API, and our own customer interfaces, are updated quarterly and available for viewing or download here: and