Second Job Tax UK 2026/27: BR, D0 Codes Explained

Starting a second job means HMRC has two PAYE sources taxing the same person. Your £12,570 Personal Allowance can only be used once, so by default HMRC gives it all to your main job and taxes the second job at BR (20%) from pound one — or D0 (40%) if your main job already put you in the higher-rate band. Here’s how the mechanics work and when to adjust them.

How HMRC decides which job is “main”

Your main job is the one that started first or pays the most — HMRC picks automatically based on the P45 or starter checklist data. The main job gets your full Personal Allowance via code 1257L (or equivalent); the second job gets a flat-rate code:

• BR — 20% on all earnings (England/Wales/NI basic rate).
• D0 — 40% on all earnings (when main job already covers the basic-rate band).
• D1 — 45% on all earnings (rare; main job already in the additional-rate band).
• SBR / SD0 / SD1 / SD2 — Scottish equivalents for Scottish residents.

This avoids accidentally giving you £25,140 of tax-free allowance (PA claimed twice).

Worked example — two jobs, basic rate

Anna has two part-time jobs in 2026/27:

• Job 1: £18,000/year (main, code 1257L).
• Job 2: £8,000/year (second, code BR).

Income Tax on Job 1:

• £0–£12,570 at 0% = £0
• £12,570–£18,000 at 20% = £1,086

Income Tax on Job 2:

• £0–£8,000 at 20% = £1,600

Total Income Tax: £2,686

If Anna had one job at £26,000 the tax would be:

• £0–£12,570 at 0%, £12,570–£26,000 at 20% = £2,686

Same amount. The BR code works correctly because Anna is a basic-rate taxpayer in both scenarios.

Worked example — crossing into higher rate

Ben in 2026/27:

• Job 1: £45,000/year (main, code 1257L).
• Job 2: £15,000/year (second, code BR).

Income Tax on Job 1:

• £0–£12,570 at 0% = £0
• £12,570–£45,000 at 20% = £6,486

Income Tax on Job 2 at BR (20%): £3,000.

But actually Ben is a higher-rate taxpayer — total income £60,000, so some of his second-job pay should be taxed at 40%. Specifically:

• £45,000 + £5,270 = £50,270 (basic rate ceiling).
• First £5,270 of Job 2 at 20% = £1,054.
• Remaining £9,730 of Job 2 at 40% = £3,892.

Total correct tax on Job 2 = £4,946 vs the BR-deducted £3,000. Ben under-paid £1,946 across the year.

HMRC reconciles this at year end via P11D/P60 — Ben will either:

1. Receive an HMRC underpayment bill in the following tax year, or
2. Have his Job 2 code changed to D0 (40%) from the next pay period once HMRC catches up.

Fix: if you start a second job and know you’re a higher-rate taxpayer, ask HMRC proactively to change the second-job code to D0. Otherwise you’ll have an unpleasant surprise after April.

National Insurance on two jobs

National Insurance is per-employment — each employer deducts NI separately with its own £12,570 primary threshold.

• Job 1 £18k: NI = (18,000 – 12,570) × 8% = £434
• Job 2 £8k: NI = 0 (below £12,570 threshold)

If Anna had earned £26,000 in one job, NI would be (26,000 – 12,570) × 8% = £1,074.

So Anna saves £640/year in NI by splitting income across two jobs — because the £12,570 threshold is applied twice. This is a legitimate effect of the per-employer NI structure, not a loophole.

NI on higher earnings: once total income crosses £50,270 (the upper earnings limit), the NI rate drops from 8% to 2%. This rate drop applies per employer — so Ben with £45k + £15k pays 8% on both jobs even though his total is above £50,270. HMRC rectifies via end-of-year reconciliation only for overpaid NI in rare circumstances — typically you don’t get a refund for this.

Splitting the Personal Allowance across jobs

If your two jobs have similar pay and you want more predictable monthly take-home, you can ask HMRC to split your Personal Allowance between them. For example, with two jobs at £12,000 each, you can split PA 50/50:

• Job 1: code 628L (£6,285 PA) — first £6,285 tax-free, rest at 20%.
• Job 2: code 629L (£6,285 PA) — same.

Result: both jobs deduct small equal amounts monthly, rather than Job 1 deducting zero tax and Job 2 deducting full 20%.

How to request: call HMRC on 0300 200 3300 or submit via Personal Tax Account → “Update your tax code” → “More than one job” → specify the split. HMRC updates typically within 1–2 weeks.

Use our two-jobs calculator

Our two-jobs calculator models exactly this scenario — input both salaries and it calculates combined Income Tax, NI per job, and the NI-saving benefit vs single employment. It handles the 8%/2% NI rate split correctly and warns you if one job pushes you into higher-rate territory where BR/D0 matters.

Freelance / self-employed as a “second job”

If your second “job” is actually self-employment (you’re a director of your own Ltd, freelancer invoicing clients, or sole trader), the tax treatment is different:

• Main PAYE job: code 1257L (full PA), 20%/40%/45% bands applied.
• Self-employed income: reported via Self Assessment; added to your taxable income for the year; taxed at marginal rate.
• Class 2 NI: mandatory Class 2 was abolished from 2024/25 — above the Small Profits Threshold (£7,105 for 2026/27) you automatically get a State Pension qualifying year without paying. Below SPT you can pay voluntary Class 2 at £3.65/week to protect qualifying years.
• Class 4 NI: 6% on profits £12,570–£50,270, 2% above.

See our sole trader vs limited company guide and the self-employed calculator for this scenario.

Related

• Two-jobs calculator — exact tax/NI split for any combination
• BR tax code page — mechanics of the 20% code
• D0 tax code page — mechanics of the 40% code
• Understanding UK tax codes
• Salary calculator — single-job take-home

Bottom line: having a BR code on your second job is usually correct. But if you’re a higher-rate taxpayer, proactively ask HMRC for D0 to avoid a year-end underpayment bill. For similar-pay dual jobs, ask HMRC to split your Personal Allowance so both codes share the £12,570 tax-free allowance.