An ID Check is required by the Government for anyone applying for a DBS.
When completing a DBS application, you will choose documents (e.g. passport, driving licence, bank statement, etc) to get checked either at the Post Office or from an LTA ID Checker.
These documents must be checked in person and once completed, you will be able to go back into your application, pay and then your DBS will be processed.
For more information on the ID Checking guidelines please see here.