Second Job Tax Calculator (How Much Will I Keep?)
Enter what you earn from your main job and the second job to see how much of the second job you actually keep.
| Second job gross pay | £8,000 |
|---|---|
| Extra income tax caused by the second job | −£1,600 |
| National Insurance on the second job (on its own) | −£0 |
| Take-home from the second job | £6,400 |
| Take-home from your main job | £25,120 |
Your second employer will usually deduct this amount through a BR tax code, so no adjustment is needed. Make sure HMRC knows about both jobs so each gets the right tax code.
How a second job is taxed
Your tax-free Personal Allowance (£12,570) is normally used up by your main job. Your second employer is then told to tax all the pay from that job using a BR tax code (20%), or a higher code if your income puts you in a higher band. So income tax on a second job is usually at least 20%.
National Insurance is worked out on each job separately. Each job has its own £12,570 threshold, so a small second job can pay little or no National Insurance, but you do not combine them to reach it.
Example: with a £30,000 main job and an £8,000 second job you pay about £1,600 income tax and £0 National Insurance on the second job, and keep £6,400.
Getting the tax right
- Tell HMRC about both jobs so they can give each the right tax code. You can do this online through your personal tax account.
- A BR code deducts 20% of the second job. If your total income is over £50,270, you may owe more, and if it is low you may be due a refund.
- Check your final tax at the end of the year. HMRC will adjust your code or ask you to pay.
Is a second job worth it?
Because the second job is taxed from the first pound, you keep about 72p of every £1 earned if you are a basic rate taxpayer, less if you are close to a higher band. Compare it with a raise using the pay rise calculator, or check your main pay with the take-home pay calculator.
Sources: GOV.UK: Tax codes. Figures last checked on 8 October 2026.
Frequently asked questions
How is a second job taxed in the UK?
Your Personal Allowance is normally used by your main job, so the second job is usually taxed at 20% (basic rate), or 40% or 45% if your total income is high enough, plus National Insurance.
Do I pay National Insurance on a second job?
Yes, on each job separately. Each has its own £12,570 threshold, so National Insurance is only due where the pay from that one job is above it.
What is the BR tax code?
BR means all pay from that job is taxed at the basic rate of 20%, with no tax-free allowance. It is usually used for second jobs.
Do I need to tell HMRC about a second job?
Yes. Update your details in your personal tax account so each employer has the right code. If your second income is self-employment, you may need to register for Self Assessment.
More from UK Answers
Figures are for the 2026/27 tax year from official sources and are estimates for guidance only, not financial or legal advice. Printed from ukanswers.co.uk.