If you do not have any suitable documents confirming your identity (e.g. a birth certificate or passport) for a professional to verify against, you have two options:

• use the eVisa Check route (online applications only)
  If you are an immigrant with your status recorded online by the UK Home Office, you can verify your identity using the eVisa Check route. This requires generating and submitting a share code for your eVisa.
• use a referee confirming from official records (Route 2)
  If you do not qualify for the eVisa Check route, you can use a referee who has access to your official records at their workplace to confirm your identity.

Referees confirming from official records (also called Route 2) are professionals, who know you and can confirm your details against their official records held at their place of work.

For more details on who can act as a referee in this circumstance, please go to Referees confirming from official records page.