Employees & PAYE
Second job tax calculator
Taken on a second job and not sure how much of it you'll actually keep? Your second job is taxed differently from your first — the pay stacks on top for Income Tax, but National Insurance is worked out separately on each job. Put both salaries in and see exactly what the second job adds to your pocket for 2026/27. Worked in your browser; nothing is sent anywhere.
Your two jobs
Rough figures are fine. This assumes both are PAYE employments on the standard Personal Allowance (one 1257L-style code across the two), England, Wales or Northern Ireland.
Why a second job is taxed the way it is
People are often shocked at how little a second job seems to add. Two rules explain almost all of it:
- Income Tax is on your total income, with one Personal Allowance. You get one £12,570 tax-free allowance across everything you earn, and it's normally used up by your main job. So your second job usually has a BR code (all taxed at 20%) or, if you're a higher earner, D0 (all at 40%). Nothing on the second job is tax-free — the allowance is already spent.
- National Insurance is worked out separately on each job. Each employment has its own £12,570 NI threshold, so a second job under £12,570 pays no employee NI at all, and even a larger one only pays 8% on the part above £12,570 of that job. This is why two modest jobs can pay far less NI than one big salary of the same total.
- The two don't always reconcile neatly. Because NI is per-job but Income Tax is on the total, your combined tax code sometimes leaves you slightly under- or over-paid on Income Tax until HMRC squares it up after the tax year. The Income Tax figure here is the correct total for the year.
If the "second job" is self-employed, this isn't your tool
This calculator is for a second employment (PAYE — you're on the payroll). If your extra income is freelance, a side hustle or anything you invoice for, it's taxed through Self Assessment instead, with its own £1,000 trading allowance and Class 4 National Insurance. Use the side hustle tax calculator for that.
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Common questions
How much tax will I pay on a second job in 2026/27?
There's no special "second job tax" rate — the pay is added to your first job and taxed at your marginal rate. For most people that's 20%, so you keep about 80% of the second job (a little less if you have a student loan or it's over the £12,570 National Insurance threshold). If the second job tips your total over £50,270, the part above is taxed at 40%. Enter both salaries above for your exact figures.
Why is my second job taxed at BR or D0?
Your £12,570 tax-free Personal Allowance can only be used once, and it's normally set against your main job. So HMRC puts a BR ("basic rate") code on the second job, taxing all of it at 20%, or a D0 code taxing it all at 40% if you're a higher-rate taxpayer. It isn't a penalty — it just stops you getting the allowance twice.
Do I pay National Insurance on both jobs?
You pay employee National Insurance on each job separately, and each job has its own £12,570 threshold. A second job paying under £12,570 a year pays no NI at all; above that you pay 8% on the part over £12,570 of that job. Because the threshold applies per job, two jobs can pay noticeably less NI than a single salary of the same total.
Will taking a second job change the tax on my first job?
Not the tax on the first job itself — that keeps your Personal Allowance and its normal code. What changes is that the second job's income is taxed on top with no allowance of its own, and your overall bill goes up by the tax and NI on the second job. The calculator shows both the combined position and what the second job adds on its own.
What if my two jobs together push me over £100,000?
Once your total income passes £100,000, your Personal Allowance is withdrawn by £1 for every £2 above it, creating a 60% effective tax rate between £100,000 and £125,140. The calculator applies this taper to your combined income automatically, so a second job that crosses £100,000 can be taxed far more heavily than you'd expect.
Do I need to do a Self Assessment tax return for a second job?
Not usually — if both jobs are PAYE, tax is collected automatically and HMRC reconciles any small difference after the year. You do need to file if the extra income isn't from an employer: freelance or side-hustle profit over £1,000, rental income, or dividends over £500. If that's you, our Tax Estimator stacks all your income together and works out the whole bill.
Is the "second job" actually self-employment?
A second job on the payroll is handled by PAYE — this page is all you need. But the moment the extra income is something you invoice for — freelancing, a side hustle, a bit of consulting — it's untaxed income, and HMRC wants a Self Assessment return that stacks it on top of your salary. The paid Self Assessment Tax Estimator does exactly that: your wage plus your self-employment profit plus any other income, with the Income Tax, the Class 4 National Insurance and the monthly amount to set aside all worked out, so the January deadline holds no surprises.
- Self Assessment Tax Estimator 2026/27 — your complete bill, salary plus self-employment plus other income, with the set-aside and payment-on-account dates worked out for you.
- Freelance Day-Rate & Profit Calculator — work backwards from the take-home you need.
- Rental Property ROI & Yield Calculator — for anyone with a buy-to-let on the side.
- Invoice Tracker & Log — paid, outstanding and overdue, automatically.
Excel and Google Sheets. Working formulas, not just formatting. Built and checked by us, with AI assistance, and every calculation verified.
Get the Tax Estimator — £9 →£9 on its own, or all four tools for £19, with a 14-day money-back guarantee.