An updated news release from the UK Government Digital Service on 14 September advised that the DCS pilot is for non-public sector organisations that want to find out if British passports are valid, and may need to do these checks as part of giving users access to an online service. The purpose of the checks must be to prevent crime. Applications to take part in the pilot are invited by 20 October.
https://www.gov.uk/guidance/apply-for-the-document-checking-service-pilot-scheme