Second job tax calculator

Common second-job mistakes

• Emergency code on the new job: until HMRC assigns BR, the second employer may over- or under-deduct. Check both codes in your tax code checker.
• Allowance on the wrong job: if the second job got your allowance and the main one got BR, you overpay. You can ask HMRC to split the allowance between jobs.
• Crossing into higher rate unnoticed: each employer only sees its own payroll; neither knows your combined income. If the total crosses a band, the underpayment surfaces later.

Two jobs pay less National Insurance than one

This is the part almost nobody explains, and it works in your favour. Income tax is charged on your total income however many jobs produce it, but National Insurance is charged per job, per pay period. Each employment gets its own £12,570 threshold, so two jobs can both sit under it while the same money in one job would not.

Identical income tax, but £914.40 less National Insurance, because neither job on its own reaches the threshold. The advantage shrinks as either job grows past £12,570 and disappears once both are comfortably above it. It is a quirk of how NI is administered rather than a loophole, and HMRC is entirely aware of it — but it does mean the “second jobs are taxed to death” folklore is often backwards for lower earners.

Do I need a separate two jobs tax calculator?

No — this is one. A two jobs tax calculator does not apply any special rate: it adds both wages together, gives the £12,570 personal allowance once, and works National Insurance out per job, which is exactly what the tool above does. The same is true for three or more jobs — the arithmetic never changes, only the number of incomes being added.

A side hustle is not always a second job

This calculator assumes both incomes are employments, taxed through PAYE. A side hustle you run yourself, selling online, freelancing in the evenings, driving, is self-employment instead, and the tax works differently: nothing is deducted at source, you report it through self-assessment, and you pay Class 4 National Insurance rather than a second lot of Class 1. The first £1,000 of that income is covered by the trading allowance and does not need reporting at all. Above it, the self-employed tax calculator is the right one. What stays the same either way is the part people get wrong: the income is added to your salary and taxed at your marginal rate, not at some separate rate of its own.

2026/27 rates, checked 28 August 2026 by Hadi. Assumes both jobs are employment (self-employed second income works differently). Method on the about page.

How to use the second job tax calculator

1. 1

   Enter the salary from your main job, the one that carries your tax code.

2. 2

   Enter the pay from the second job.

3. 3

   Read the combined tax, which is worked out on both incomes together, not at a separate second-job rate.

4. 4

   Check the National Insurance line, because each job has its own threshold and that is where the surprise usually is.

When should you use the second job tax calculator?

Use it when you have or are considering two incomes, since they are taxed together on one allowance rather than at a separate second-job rate.

Where to go next

• Tax code checkerTo understand the BR code on the second job.Open
• Self-employed tax calculatorTo if the second income is freelance rather than employed.Open
• Household income calculatorTo add a partner's income to see the household picture.Open

All 51 calculators share one tested engine, so a figure from the second job tax calculator agrees with every other page here. See the full calculator index or the pay and tax guides.