How much tax will I pay on a second job?
Why a second job looks taxed more heavily than it is, what the BR tax code actually means, and how to work out the real deduction.
Here’s the myth-buster first: there’s no special higher tax rate for a second job. It only looks that way. Your tax-free personal allowance — £12,570 — is usually all used up by your main job, so your second job is taxed from the very first pound, typically at 20%. You’re not being penalised for working twice; you’ve simply already spent your tax-free slice.
The quick answer
A second job is normally taxed at 20% from the first pound, because your £12,570 personal allowance is already applied to your main job. It’s given a “BR” tax code, meaning basic rate with no allowance. If your combined income crosses £50,270, the part above that is taxed at 40%. There’s no separate “second job rate” — your total income across both jobs decides the bands, exactly as if it were one salary.
The myth, and why it persists
Ask around and you’ll hear that second jobs are “taxed more.” It’s one of the stickiest myths in UK pay, and it’s wrong — but you can see why people believe it. When the payslip from your second job shows 20% gone from the very first pound, while your main job had a chunk that was tax-free, the second job feels punished.
What’s actually happening is simpler and fairer. Everyone gets one personal allowance — £12,570 a year you can earn before any income tax. You don’t get a second one for a second job. HMRC applies that single allowance to your main (usually highest-paid) job through the standard 1257L tax code, and gives your second job a “BR” code, which means every pound is taxed at the basic 20% rate with no allowance attached. The tax is the same as if you’d earned the lot in one job; it’s just that the tax-free part has already been used.
The proof is in the arithmetic. Earn £30,000 in a main job and £8,000 in a second, and your total income tax is identical to what someone earning a single £38,000 salary pays — to the pound. The second job isn’t taxed at a higher rate; it’s taxed at exactly the rate that slice of your total income would attract anyway.
The tax codes you’ll see
Your second job’s tax code tells you which rate is being applied. Three are common, and which you get depends on your total income.
| Code | What it means | When you’ll see it |
|---|---|---|
| BR | All income taxed at basic 20%, no allowance | Most second jobs, total income under £50,270 |
| D0 | All income taxed at higher 40% | When your main job already fills the basic band |
| D1 | All income taxed at additional 45% | Top earners with a second income above £125,140 |
If both jobs together stay within the basic-rate band, BR gets it right and you’ll owe nothing extra at year end. The trouble starts when your combined income crosses £50,270 but your second job is still on a BR code — then it’s only deducting 20% where some should be 40%, and you can quietly build up an underpayment. It’s worth checking your codes if you’re near that line.
Don’t forget National Insurance
Income tax looks at your total income across both jobs; National Insurance doesn’t. NI is worked out separately for each job, against each job’s own threshold. For 2025/26, you pay employee NI at 8% on earnings above £242 a week in a given job, and nothing below that.
The quirk worth knowing: because NI is per-job, a modest second job can escape NI entirely while your main job pays it. That’s a small silver lining to the personal-allowance story — you lose the tax-free allowance on the second job, but you may dodge NI on it if it’s small enough.
When you can split your allowance
Two low-paid jobs
If neither job pays above £12,570, ask HMRC to split your allowance between them so you’re not overtaxed on one.
Stable hours
Splitting works best when income is predictable. If one job’s pay jumps, a split can leave you underpaying and facing a bill.
It’s not automatic
HMRC won’t split the allowance for you. You have to ask — otherwise the full allowance sits on your main job by default.
Crossing £50,270
If both jobs combined push you into higher rate, tell HMRC so your codes are corrected and you avoid a year-end surprise.
A worked example
Main job £45,000, second job £12,000
Here the combined income crosses £50,270, so part of the second job is taxed at 40%. A plain BR code would only take 20% — which is why this earner should ask HMRC to adjust, or face an underpayment. The 40% isn’t a “second job penalty”; it’s the higher-rate band their total income reached.
The takeaway: your second job is taxed exactly as your total income dictates, no more and no less. The only real risk is a tax code that hasn’t caught up with your combined earnings. The fastest way to see your true take-home is to run both salaries through the numbers together.
Common questions
Is a second job taxed at a higher rate?
No. There’s no special tax rate for second jobs. A second job is usually taxed at the basic 20% rate from the first pound because your £12,570 personal allowance is already used by your main job. The total tax you pay is the same as if you’d earned the combined amount in a single job — the tax-free part has simply already been allocated.
What does a BR tax code mean?
BR stands for Basic Rate. It means all income from that job is taxed at 20% with no personal allowance applied. It’s the most common code for a second job, on the assumption your allowance is being used elsewhere. If your combined income is higher, you may instead see D0 (40%) or D1 (45%).
How much tax will I pay on a £8,000 second job?
If your main job already uses your personal allowance and your total income stays within the basic-rate band, an £8,000 second job is taxed at 20%, giving £1,600 of income tax. If the second job is small enough to stay under £242 a week, it pays no National Insurance, since NI is assessed per job.
Do I pay National Insurance on a second job?
Only if that job pays above the threshold. National Insurance is calculated separately for each job, so you pay employee NI at 8% on earnings above £242 a week in each role for 2025/26. A second job earning below that weekly threshold pays no NI, even if your main job is well above it.
Can I split my personal allowance between two jobs?
Yes, if neither job pays more than £12,570. You can ask HMRC to split your allowance so part of it applies to each job, avoiding overpayment on a low-paid main job. HMRC won’t do this automatically — you have to request it — and it works best when your income from each job is stable and predictable.
Will a second job push me into a higher tax band?
It can, if your combined income crosses £50,270. At that point the portion above the threshold is taxed at 40%. This isn’t a penalty for the second job specifically — it’s simply the higher-rate band that your total income has reached. If you’re near the line, tell HMRC so your tax codes are correct and you don’t underpay.
Could I end up with a tax bill from a second job?
Yes, if your tax code doesn’t match your real situation. The common trap is a BR code (20%) on a second job when your combined income has crossed into higher-rate territory, meaning not enough is deducted through the year. Checking your codes with HMRC when your circumstances change is the simplest way to avoid an unexpected bill.
Related tools & guides
How we put this together
Figures use HMRC income tax rates and thresholds for 2025/26 (England, Wales and Northern Ireland): a £12,570 personal allowance, 20% basic rate to £50,270, 40% higher rate to £125,140, and 45% above. Tax codes (BR, D0, D1) follow HMRC’s standard definitions for second employments.
National Insurance figures use the 2025/26 employee Class 1 threshold of £242 a week and an 8% main rate, assessed per job. Worked examples are calculated directly from these bands and cross-checked. Scotland sets its own income tax bands, which differ from the figures above.
We review this guide when HMRC updates rates, thresholds or tax-code rules.