UK Two Jobs Tax Calculator

The total income tax on two jobs equals the tax on one combined salary of the same total — HMRC reconciles at year end. But during the year, the withholding from your second job is often too low or too high depending on its tax code, and HMRC catches up via a P800/Simple Assessment. You typically pay less National Insurance with two jobs because each employment has its own £12,570 Primary Threshold.

HMRC usually puts your primary job on 1257L (full Personal Allowance) and your second job on BR (flat 20%). If your second job pushes you into the higher-rate band, BR withholds too little and you'll owe tax at year end. HMRC may issue D0 (40%) or D1 (45%) for your second job if your combined income is high. 0T gives no PA but applies progressive bands from zero.

Class 1 NI is calculated separately for each employment. Each job has its own £12,570 Primary Threshold and £50,270 Upper Earnings Limit. This is usually to your advantage: two £20,000 jobs pay NI on £14,860 combined, while one £40,000 job pays NI on £27,430.

If your second job is on BR but your combined income pushes you into the 40% higher-rate band, yes — BR only withholds 20% but you owe 40% on the higher portion. HMRC sends a P800 Simple Assessment after the year closes. If you've been over-withheld (e.g., second job on D0 when you're a basic-rate taxpayer), HMRC issues a refund.

No. If both employers apply the full £12,570 Personal Allowance, you'll be dramatically under-withheld — potentially thousands of pounds. HMRC allocates the PA to one job (usually your primary) and puts the other on BR/D0/D1/0T. If you spot both jobs on 1257L, contact HMRC immediately to get the second job's code corrected.

Student loan repayments are calculated per-job, so each employment checks your salary against the plan threshold independently. If each job is below the threshold (e.g., Plan 2 at £28,470), neither employer withholds anything — but HMRC reconciles against combined income at year end and may collect what's owed.