Second Job Tax Calculator 2025/26
Calculate how much you actually take home from a second job after Income Tax and National Insurance. Enter both salaries to see the combined tax impact and the effective rate on your second income.
Your Jobs
Second Job Take-Home
£0
0% effective rate on second job
Main Gross
£0
Second Gross
£0
Main Tax
£0
Second Tax
£0
Main NI
£0
Second NI
£0
Main Net
£0
Effective Rate
0%
Second Job Net
£0
How Second Job Tax Works in the UK
Income Tax in the UK is calculated on your total income from all sources. Your Personal Allowance (£12,570) is usually applied to your main job via your tax code (1257L). Your second employer will typically use a BR code, which means all second job earnings are taxed at 20% from the first pound.
If your combined income from both jobs exceeds £50,270, some of your earnings will be taxed at the higher rate of 40%. HMRC may issue a D0 code for your second job in this case, taxing all second job income at 40%.
National Insurance is calculated separately for each job. Each employment has its own Primary Threshold (£12,570 annually), so you only pay NI on second job earnings above this threshold. If you have two low-paying jobs, you might not pay NI on either even though your combined income would trigger NI with a single employer.
What You Need to Know About Second Job Tax
The most common mistake people make is assuming their second job is taxed separately. While NI is per-job, Income Tax is on your total income. If you are a basic rate taxpayer on your main job and add a second job, that second income may push you into the higher rate band.
You can split your Personal Allowance between jobs by contacting HMRC, but most advisers recommend keeping it on your highest-paying job. If you leave a job mid-year or your income changes, check your tax code promptly — the wrong code leads to over or underpayment that takes months to correct.
Frequently Asked Questions
How is a second job taxed in the UK?
Your second job income is added to your first for Income Tax. Your Personal Allowance is usually on your main job, so second job earnings are taxed from the first pound using a BR (20%) or D0 (40%) code. NI is calculated separately per job.
Do I get a tax-free allowance on my second job?
Not usually. Your £12,570 Personal Allowance is applied to your main job. You can ask HMRC to split it between jobs, but most people leave it on their primary employment for simplicity.
Do I pay National Insurance on both jobs?
Yes. NI is calculated per employment separately. Each job has its own threshold of £12,570. If both pay above this, you pay NI on both. If you overpay NI you can claim a refund from HMRC.
Will a second job push me into a higher tax bracket?
It can. If your combined income from both jobs exceeds £50,270, earnings above that threshold are taxed at 40%. Above £125,140, the additional rate of 45% applies.
What tax code will my second job use?
Most second jobs use BR (basic rate 20% on everything). If combined income exceeds £50,270, HMRC may issue D0 (40% on everything). Check your codes via your Personal Tax Account.
How do I avoid overpaying tax on a second job?
Check your tax codes are correct via HMRC's online portal. If you leave a job mid-year you may overpay — file a P800 or Self Assessment to claim a refund. Keep both employers informed of your situation.
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