Employers are legally required to verify that all employees have the right to work in the UK. The documents you need to provide for this check depend on your nationality.
If you are a British or Irish citizen
You can prove your right to work by providing a copy of your current or expired British or Irish passport.
If you are not a British or Irish citizen
You need to provide a share code, which is an alphanumeric code generated online through the UK government's website. Your employer will use this code, along with your date of birth, to securely access your digital immigration status and confirm your eligibility to work.
Your share code is valid for 90 days and can be used multiple times during that period.
How to get a share code
Go to the official gov.uk website for proving your right to work.
Follow the instructions to log in to your UK Visas and Immigration (UKVI) account. You may need your Biometric Residence Permit (BRP) number, Biometric Residence Card (BRC) number, or other immigration document details.
Generate the share code for the purpose of a "right to work" check.
You can then share the code with your employer, who will verify your status online.