Tax codes
Why your tax code might change
HMRC may update your tax code if:
- you start a new job
- you get taxable state benefits
- you start to get income from an additional job or pension
- your weekly State Pension amount changes
- your employer tells HMRC you have started or stopped getting benefits from your job
- you claim Marriage Allowance
- you claim expenses that you get tax relief on
You may also be put on an emergency tax code if you change jobs and HMRC does not get your income details in time.
If your tax code has changed, you can use the Check your Income Tax online service to find out why.