Second job tax explained: what BR, D0 and D1 mean, when you get each, why second-job earners overpay, and how to split your allowance to fix it.
If you’ve picked up a second job and the whole second payslip seems to vanish into tax, you’ve met one of the three “no allowance” codes: BR, D0 or D1. They look cryptic, but each one is just a flat rate applied to every pound that job pays you.
Second job tax trips people up because the rules feel unfair until you see the logic. Your personal allowance can only sit on one job at a time, so the second job often gets taxed from the very first pound. Here’s what each code means, when you’d get it, and how to fix it if you’re paying more than you should.
All three codes mean “no personal allowance on this income, tax every pound at one flat rate”. The only difference is the rate.
The letters are a shorthand HMRC sends to your second employer so their payroll knows not to apply any tax-free band. Your main job keeps that band, normally on code 1257L, which protects your first £12,570 for the 2026/27 tax year.
Picture your income as one stacked pile, even though it comes from two employers. HMRC fills the tax bands from the bottom up: your personal allowance first, then the 20% band up to £50,270, then 40% up to £125,140, then 45% above that.
Your main job sits at the bottom of the pile and gets the allowance. The second job sits on top, so it’s taxed at whatever rate your income has already reached. That’s the whole reason for BR, D0 and D1: they tell the second employer which band you’re already standing in.
Worked example. You earn £35,000 in your main job on 1257L, and £8,000 in a weekend job on BR.
National Insurance is calculated separately for each job, not stacked. For 2026/27 each job only starts charging employee NI once it pays you more than £1,048 a month. A small second job under that figure pays no NI at all, which sometimes softens the tax sting.
The code your second employer receives depends on how much your main job already earns.
BR (20%) is the default for most second jobs. You’ll get it when your main job pays more than your personal allowance but your total income stays inside the basic-rate band, under £50,270. This covers the majority of people with a main job and a side job.
D0 (40%) appears when your main job already uses up the entire basic-rate band. If your main salary is above roughly £50,270 for 2026/27, every pound of the second job is higher-rate income, so HMRC sets it to 40%. Sales staff who earn a big basic plus commission often see D0 land on a second income.
D1 (45%) is rare. You’ll only see it if your main job pushes you past £125,140 and into additional-rate territory, so the second job is taxed at 45% from the first pound.
One caveat for Scotland. Scottish taxpayers have their own bands and their codes carry an S, so you’d see SBR, SD0, SD1 and SD2 instead, with Scottish rates. The principle is identical, only the percentages change.
The classic trap is two low-paying jobs. BR assumes your main job has already used your full personal allowance. If it hasn’t, the unused allowance is wasted, and you overpay.
Worked example. You have two part-time jobs, each paying £10,000 a year. The first is on 1257L, the second on BR.
You’ve paid £2,000 when you owed £1,486. That’s £514 sitting with HMRC because BR couldn’t see the £2,570 of allowance your main job left unused. The code isn’t broken, it just can’t read across two employers on its own.
The opposite problem catches higher earners. If a second job stays on BR when your main salary has already crossed £50,270, you’ll be taxed at 20% on income that should be 40%, and you’ll owe the difference at year end. That’s why a D0 code, annoying as it looks, is often protecting you from a surprise bill.
Commission and bonus earners hit a version of this every pay run. Say your main sales job pays a modest basic but a big quarterly commission tips your annual total over £50,270 in some months and not others. HMRC often sets a second income to D0 to be safe, so it taxes the lot at 40% even in a quiet quarter when you didn’t actually reach higher rate. You don’t lose that money, it comes back when both jobs are reconciled after 5 April, but it can leave your take-home looking thinner than the numbers say it should be. If your income swings month to month, it’s worth checking your codes a couple of times a year rather than setting and forgetting.
Sorting out second job tax starts with finding the codes. Check the top of each payslip, or open the HMRC app and look at “your tax codes”. You should see one main code, usually 1257L, and one of BR, D0 or D1 on the second job.
If the codes match your income, you’re fine, leave them alone. If you think you’re overpaying because your main job doesn’t use your full allowance, you can ask HMRC to split your personal allowance across both jobs. They’ll move part of your £12,570 onto the second job, giving it a normal-style code instead of BR, so each wage gets a slice of tax-free pay.
Two ways to do it: update your job and income details in the HMRC app or your Personal Tax Account, or call HMRC on 0300 200 3300 and ask them to divide your allowance between the two employers. It’s worth knowing how the BR code works before you ring, so you can tell them roughly how much each job pays. Our guide to the BR tax code covers that in more detail, and if your second job has landed on 0T instead of BR, that’s a slightly different situation worth reading up on.
If the tax year has already ended and you overpaid, you usually don’t need to chase it. HMRC reconciles both jobs after 5 April and sends a P800 if you’re owed money. If you started a job mid-year and got hit by emergency tax, that often sorts itself out the same way.
The mechanics of BR, D0 and D1 are unchanged for 2026/27. The rates are still 20%, 40% and 45%, and the personal allowance is still frozen at £12,570, where it’s scheduled to stay until April 2028. The higher-rate line holds at £50,270 and the additional-rate line at £125,140.
What did shift is how you hear about code changes. Since April 2026, HMRC sends most tax code notices digitally first, so a new code on your second job may appear in the app rather than in a letter. If your second payslip suddenly switched from BR to D0, or the other way, check the app for the notice rather than waiting for post that may never arrive.
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It depends which code your second job is on. BR taxes the whole second wage at 20%, D0 taxes it all at 40%, and D1 taxes it all at 45%. Your main job keeps your personal allowance on code 1257L, so the second job usually gets no tax-free band of its own.
BR is right if your main job already uses up your full £12,570 personal allowance and your total income stays under £50,270. If your main job earns less than the allowance, BR can make you overpay, because it ignores the unused part. You can ask HMRC to split your allowance across both jobs instead.
A D0 code means HMRC expects your main job to use up all of your basic-rate band, so every pound from the second job falls into higher-rate territory. If your main salary is above roughly £50,270 for 2026/27, D0 on the second job is usually correct.
If you overpaid because BR ignored your unused personal allowance, HMRC usually reconciles it after the tax year ends and refunds you, often through a P800 letter. To stop it happening again, call HMRC on 0300 200 3300 and ask them to split your allowance between your two jobs.
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A note on financial advice: NetPay UK calculates take-home pay based on official HMRC tax rules. This article reflects rules in force at the time of publication (7 June 2026). Tax rules change. For complex situations, consult a qualified UK accountant or visit gov.uk/income-tax.
