Guidance

Changes to your tax code when you start a new job

Find out why HMRC may contact you if your tax code changes due to a change in employment.

If you did not have a P45 from a previous employer when you started your new job, your new employer should have asked you to complete a starter checklist.    

If you did not fill this in, or you completed it incorrectly, you may have been given a BR or 0T tax code.  

Find out more about what your tax code means.

If we’ve identified that you’ve been given a BR or 0T tax code incorrectly, we may have already told you that:  

  • your tax code has been corrected (based on the information we hold) 
  • a new tax code has been sent to your new employer  

You can check your payslip to see when the new tax code is applied.  

You should speak to your employer if the change to your tax code has not been applied by your:

  • next pay day, if you are paid monthly 
  • third pay day, if you are paid weekly

You can also check your tax code and Income Tax in your Personal Tax Account.

If you’ve overpaid tax in your new job 

Your new tax code will make sure any overpayments are paid back to you through your pay if you either: 

  • have not been employed and have never received any of the state benefits listed in Statement C of the starter checklist in the current tax year 
  • selected Statement C in error, and we’ve received leaver pay and tax information from your previous employer in the current tax year 

If your previous employer does not confirm that you’ve ended your employment with them, we’ll tell you if you’ve overpaid any tax after the current tax year has finished.  

Find out more about tax overpayments and underpayments.

Published 1 December 2023