In almost all cases it is not possible to verify your identity using an expired document.
The exception is when entering UK passport details using the manual form on our webpage (ie. typing in the details yourself). In this case it is possible to provide a passport that is within six months of expiry.
In all other situations (including when uploading a UK passport via the Digidentity app), it is only possible for valid documents to be accepted.
For more information on our document requirements, please see: What documents will I need to prove my identity?