Question 1

How is tax calculated on a second job?

Accepted Answer

Each employer runs PAYE independently. Your personal allowance is usually applied to your main job, so the second job is often taxed at the basic rate on all earnings using a BR tax code.

Question 2

Will I overpay National Insurance with two jobs?

Accepted Answer

If both jobs pay above the Primary Threshold you will pay NI on each one separately. If the combined NI exceeds the annual maximum, you can apply to HMRC for a deferment or claim a refund after the tax year ends.

Question 3

What tax code will my second job have?

Accepted Answer

Usually BR (basic rate), which means 20% on all earnings with no personal allowance. If you are a higher-rate taxpayer, HMRC may issue D0 (40%) instead. You can ask HMRC to split your allowance between jobs.