Tax on a Second Job UK in 2026/27: What You Actually Pay

Around one in twenty-five UK workers has more than one job, and almost everyone who takes on a second job has the same reaction to the first payslip: it looks like the taxman has taken nearly half of it. There is no special "second job tax" — but there is a specific reason it looks that way, and a specific reason yourNational Insurance bill can come out lower than you'd expect too.

Why your second job gets taxed harder

You only get one tax-free Personal Allowance (£12,570 in 2026/27), and PAYE has to decide which employer uses it. By default, HMRC gives the whole allowance to the job it treats as your main one — usually whichever you started first or which it estimates pays the most — using the standard tax code 1257L. Every other job then gets a code with no allowance built in at all, almost always BR, which taxes all of that job's pay at the basic rate of 20% from the first pound. If your combined income is high enough that some of it should be taxed at 40% or 45%, you may instead see D0 (40%) or D1 (45%) on the second job.

This is a reasonable working assumption for HMRC to start with, not a penalty — and, as the worked example below shows, it often collects exactly the right total tax by the end of the year. See gov.uk: How tax works if you have more than one job for HMRC's own explanation of the allowance and code rules.

Worked example: two modest jobs

Someone earning £18,000 in their main job and £9,000 in a second job, both under the £50,270 higher-rate threshold, pays this through PAYE for £18,000 on a standard 1257L code and £9,000 on BR:

The Income Tax comes out identical either way — £2,886 total, because all of both jobs still falls inside the 20% band. National Insurance does not: paid as two separate jobs it comes to£434, against £1,154 if the same £27,000 were earned from one employer — a saving of £720 a year. That's not a loophole: it's how NI is designed to work.

Why National Insurance is different from Income Tax

HMRC's internal guidance on this is explicit: "contributions for each employment are normally calculated separately" (HMRC National Insurance Manual, NIM10003), unless the two jobs are with "associated" employers, in which case the earnings are aggregated and NI is worked out on the total. For two unrelated employers, each one applies the £12,570 Primary Threshold on its own payroll, with no visibility of what the other is paying you. A second job that stays under that threshold by itself contributes nothing to your NI bill, however much your main job pays.

If both jobs pay well — broadly, £967 a week or more from one and £242 a week or more from a second (with three or more jobs: £1,209 a week or more from two of them and £242 a week or more from another) — you can end up overpaying NI instead, because each employer applies the full 8% rate up to its own upper limit. HMRC lets you apply to defer part of one job's NI to a reduced 2% rate using form CA72A; for the 2026/27 tax year, HMRC must receive your application by 14 February 2027 (gov.uk: Defer your National Insurance). This only helps if you are a genuinely high earner across two or more jobs — most people with a second job are on the saving side shown above, not the overpaying side.

When the BR code gets it wrong: crossing into higher rate

The BR code only works out exactly right while both jobs stay inside the basic-rate band. Someone on£45,000 in their main job plus £10,000 in a BR-coded second job has PAYE deduct £8,486 in Income Tax across the two payslips. But £55,000earned as one salary would owe £9,432 — £946 more — because part of that income sits above the £50,270 higher-rate threshold and should be taxed at 40%, not the flat 20% that BR applies. HMRC usually catches this later and corrects it through a tax code change, a Simple Assessment, or (if you already complete one) your Self Assessment return — you don't need to do anything proactively, but it's worth not spending a refund you haven't actually been given.

Second job, fixed at £8,000: how the gap changes with your main salary

Figures below hold the second job at a fixed £8,000 on a BR code and vary the main job, 2026/27 rates, England, Wales and Northern Ireland:

The tax gap stays at £0 while the main job alone is under the higher-rate threshold, then opens up once the main job's own salary already uses the full basic-rate band — at that point the whole second job should be at 40%, not 20%. The NI saving is largest (£640 a year, the maximum possible on an £8,000 second job at the 8% rate) while the second job stays under the £12,570 threshold on its own, and shrinks once the main job alone is already above the £50,270 upper limit, because the "one combined job" comparison is then mostly taxed at the lower 2% rate anyway.

Scotland: the same mismatch can bite sooner

Scotland has more income tax bands than the rest of the UK, so a BR-coded second job (still 20%, the Scottish basic rate) can under-collect even when neither job looks close to "higher rate" individually. A£24,000 main job plus a £8,000 BR-coded second job has PAYE deduct £3,846 — but the same £32,000 as one Scottish salary owes£3,871, a gap of £25, because part of the combined income crosses from the 20% basic band into the 21% intermediate band. See our Scottish tax bands guide for the full set of rates.

What to do about it

• Check both tax codes. Use your Personal Tax Account or the HMRC app to confirm which job has 1257L and which has BR, D0 or D1, and that HMRC knows about both employers.
• Ask HMRC to move your allowance if your "main" job by HMRC's assumption actually pays less than your second one — you can ask for it to be split or reallocated.
• Don't assume a refund is final. If your combined income crosses £50,270, expect HMRC to collect the difference later via a tax code adjustment, Simple Assessment or Self Assessment.
• Keep a buffer if you're close to the higher-rate threshold across two jobs, in case of a later bill.

Our salary calculator can model a single job's tax code directly — enter BR, D0 or D1 in the tax code field to see exactly what a second job on that code will deduct, or use the standard code to check your main job's figures.

Quick answers

Why is my second job taxed so heavily?

HMRC gives your tax-free Personal Allowance (£12,570 in 2026/27) to what it treats as your main job — usually the one you started first or the one that pays more. Your second job then gets a BR tax code, which taxes every pound at the basic rate (20%) with no allowance at all, which is why a new second job can feel like it's "all going in tax" from the first payslip.

Will I end up paying too much tax overall?

Not usually, as long as both jobs together stay inside the basic-rate band: a £18,000 main job plus a £9,000 BR-coded second job is taxed at £2,886 split across the two payslips — exactly what one £27,000 job would owe. The risk is if your combined income crosses £50,270: the BR code keeps taking 20% from the second job when part of it should be 40%, which can leave you owing extra later.

Do I pay less National Insurance if I have two jobs instead of one?

Often, yes. Unlike Income Tax, NI is worked out separately for each employer against the same annual Primary Threshold (£12,570), with no aggregation across jobs by default. A second job that stays below that threshold on its own pays no NI at all, even though the same money earned in one combined job would be taxed above the threshold.

Can I ask for my Personal Allowance to go to my second job instead?

Yes — contact HMRC (online via your Personal Tax Account or the HMRC app, or by phone) and ask them to split or reallocate your allowance. This is worth doing if your "main" job by HMRC's assumption actually pays less than your second one.

What if my tax code is wrong and I've underpaid?

HMRC usually corrects it automatically: either through a tax code adjustment for a later year, a Simple Assessment or P800 calculation, or (if you already file one) your Self Assessment return. You do not need to do anything unless HMRC asks you to pay a specific amount by a specific date.

Related

• Tax Codes Explained: What Your Tax Code Means
• National Insurance Rates 2026/27
• Scottish Tax Bands 2026/27