by Asim Abbas
11 November 2026 
Tax on a second job: tax codes, NI and avoiding overpayments
Tax on a second job: tax codes, NI and avoiding overpayments
More people than ever have a second job, whether it’s weekend shifts, evening work or a part-time role alongside a main career.
- Your personal allowance usually goes against your main job
- Second jobs often use the BR tax code
- National Insurance is worked out separately for each job
- You can ask HMRC to split your allowance if needed
Second jobs are taxed differently from your main job, and getting the tax code wrong can mean paying too much, or too little, for months.
This guide explains how second jobs are taxed in 2026/27, how National Insurance works and how to fix common problems.
How second jobs are taxed
You get one personal allowance of £12,570, not one per job. HMRC normally gives it all to your main job, so your main employer uses a code like 1257L. Your second employer then usually uses the BR code, which taxes every pound at 20%.
| Code | What it means |
|---|---|
| 1257L | Full personal allowance used in this job |
| BR | All income taxed at the basic rate, 20% |
| D0 | All income taxed at the higher rate, 40% |
| D1 | All income taxed at the additional rate, 45% |
| 0T | No allowance, taxed through all bands |
If your combined income takes you into the higher rate band above £50,270, HMRC may change your second job code to D0.
Tax code checker
Check both of your tax codes.
National Insurance on two jobs
Unlike Income Tax, employee National Insurance is worked out separately for each job. Each employer applies the threshold of £12,570 a year (£242 a week) on its own. So a small second job may attract no NI at all, even if your main job does.
Jess earns £30,000 in her main job with a 1257L code, and £8,000 from weekend work on a BR code. Her second job pays tax of £1,600 (20% of £8,000). Because the weekend job is under the NI threshold, she pays no National Insurance on it. Her total tax across both jobs is £5,086, which matches her full-year liability.
When to split your allowance
If your main job pays less than £12,570, part of your personal allowance is wasted there while your second job is taxed at 20% on every pound. You can ask HMRC to move the unused part to your second job. This is common for people with two part-time jobs.
- Use your HMRC personal tax account or the HMRC app
- Tell HMRC the expected pay from each job
- HMRC sends new codes to both employers
Fixed-fee accountancy support
Transparent monthly packages for sole traders, landlords and limited companies. Fixed fees agreed upfront, VAT included.
Get a fixed-fee quoteCall 0161 531 4179Common problems
- Both jobs using 1257L: you’ll underpay and get a bill later
- An emergency code: a new second job may use 1257L W1 or M1 until HMRC updates it
- Wrong main job: if HMRC gives the allowance to the smaller job, you may overpay
- Combined income near £100,000: the personal allowance tapers, which codes may not pick up
Do you need a tax return?
Not usually, if both jobs are taxed through PAYE. You may need one if your total income is over £150,000, you have self-employed or rental income, or you need to pay the High Income Child Benefit Charge. If your second job is self-employed, such as freelancing or delivery driving, see our side hustle guide.
Check your codes with our tax code checker, read our guide to tax codes, or see HMRC’s guidance on tax codes.
What should I do next?
Look at the tax codes.
It should get the allowance.
Via your personal tax account.
Frequently Asked Questions
Why is my second job taxed at 20%?
Your personal allowance is usually used by your main job, so the second job uses the BR code.
Do I pay National Insurance on two jobs?
NI is worked out separately for each job. A small second job may have no NI deduction.
Can I split my personal allowance between jobs?
Yes. Ask HMRC to move unused allowance from your main job to your second job.
Do I need to file a tax return for a second job?
Usually not, if both are taxed through PAYE.
What does a D0 code mean?
All pay from that job is taxed at 40%. It is used when your total income is in the higher rate band.
Need help with this? Wingate Accountants offers fixed-fee online accountancy support across the UK. Call 0161 531 4179 or request a quote at wingateaccountants.co.uk.
About the Author
Asim Abbas
I’m Asim Abbas, founder of Wingate Accountants and a Chartered Certified Accountant. I help sole traders, landlords and directors stay on top of their tax with fixed fees and plain-English advice.
