Second Job Tax Calculator UK 2026/27

Your second job is taxed at the same rates as your first — 20%, 40%, or 45% — but with no Personal Allowance applied. Most people receive a BR code (20%) on their second job. If your main job salary already exceeds £50,270, your second job is taxed at 40% (D0 code). Above £125,140 it is 45% (D1). Your total tax bill on the same combined income is identical to earning it all from one employer.

BR stands for Basic Rate. It means all your second job income is taxed at 20% with no tax-free Personal Allowance applied. HMRC issues it when your main job already uses your full £12,570 allowance and your combined income stays within the basic rate band (below £50,270). If combined income exceeds £50,270, HMRC may issue a D0 code (40%) instead.

Yes — if your earnings from the second job exceed the NI Primary Threshold (£12,570 a year, or £242 a week) in each pay period. NI is calculated per employer and per pay period. If your main job already earns above £50,270, your second employer will still charge 8% NI on your second job earnings up to £50,270 — creating an overpayment that HMRC refunds after the tax year.

D0 means all your second job income is taxed at 40% — the higher rate — with no Personal Allowance. HMRC issues D0 when your main job salary fills the entire basic rate band (£50,270 or above), so all second job income falls into the higher rate band from the first pound. If HMRC applies D0 but your combined income doesn't reach £50,270, you'll be overtaxed and will receive a P800 refund.

Yes — you can ask HMRC to split your Personal Allowance between two employers using a split tax code. For example, if your main job pays £8,000 and your second job pays £10,000, HMRC can allocate £8,000 allowance to the first job (code 800L) and £4,570 to the second (code 457L). Contact HMRC via your Personal Tax Account or call 0300 200 3300 to request this.

HMRC will issue a P800 tax calculation after the tax year showing any overpayment. Common causes include an emergency tax code applied when starting the second job, a D0 code when only part of your second job income falls into the higher rate, or NI overpayment when your main job is already above the Upper Earnings Limit. You can also claim in-year refunds through your HMRC Personal Tax Account. Overpayments can be reclaimed for up to 4 years.

Self-employed second income is added to your total income and taxed through Self Assessment. You pay income tax on profits at the same rates — 20%, 40%, or 45% depending on combined income. NI differs: instead of employee NI (8%/2%), you pay Class 4 NI (6% on profits between £12,570 and £50,270, then 2% above) and Class 2 NI (£3.65/week if profits exceed £7,105). You must register for Self Assessment if self-employed profits exceed £1,000.

Once your combined income from all jobs and sources exceeds £100,000, your Personal Allowance is tapered — reduced by £1 for every £2 above £100,000. The allowance is fully withdrawn at £125,140. This creates an effective marginal tax rate of 60% on income between £100,000 and £125,140. If your combined income is in this range, it may be worth making pension contributions to reduce your adjusted net income below £100,000.