Multiple Jobs and Tax Codes: What UK Employers Need to Know

When an employee has more than one job, their Personal Allowance — the amount they can earn before paying income tax — is usually applied to their primary employment. The secondary employment is taxed at basic rate from the first pound using a BR tax code. This can mean an employee pays more tax across both jobs in the short term until HMRC issues a corrected code.

HMRC resolves this when it becomes aware of the multiple employment situation — typically through RTI data. If the employee contacts HMRC to ask for their allowance to be split between jobs, HMRC will issue amended codes to both employers. As an employer, when you receive a P6 notice with a new tax code for an employee, you apply it from the next pay run. You cannot change a tax code without a HMRC instruction to do so.

If an employee comes to you claiming their tax code is wrong, direct them to HMRC directly — via the online personal tax account or by phone. You operate the code HMRC gives you. This is not an area where employers have discretion, and applying the wrong code — even with good intentions — creates complications for both parties at year-end.