The YBS API Developer Portal is where developers can learn about and use APIs for YBS services and customers. By signing up you can start building against the sandbox APIs, check out our Getting Started Guide for more information.

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

Start by signing up for a developer account, it’s free and you’ll have immediate access to the sandbox APIs. Here you’ll be able to build and test new apps and experiences with a limited subset of data available.

Before you get going you’ll need to add a new app to your account which will generate a client key and secret, you’ll need this to make any API calls. Follow our Getting Started Guide to learn more.

Currently YBS offers read-only APIs for accessing account and balance information on customer Payment Accounts. In line with PSD2 regulation these APIs will be expanded to include payment functionality.

Got a great idea but need an API we don’t currently have listed? Get in touch via our Contact form.

Developers with access to the production environment will be notified via email of any upcoming changes. You will be given notice before an API is deprecated, please be sure to add to your safe senders list in order to keep up to date.

Yes, when you make an API call you will need to specify which brand the account is from. 
When building services for YBS 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.