Tax on a £12,000 second job with a £35,000 main job
With a £35,000 main job using your Personal Allowance, a £12,000 second job costs £2,400 Income Tax and £0 National Insurance. You keep £9,600 of the £12,000, and £38,320 a year from both jobs together.
| Main job salary | £35,000 |
| Second job salary | £12,000 |
| Income Tax on both jobs | £6,886 |
| Income Tax due on the second job | £2,400 |
| National Insurance on the second job | £0 |
| Second job take-home per year | £9,600 |
| Main job take-home per year | £28,720 |
How this is worked out
You get a tax code for each job. BR taxes all pay from a job at the basic rate and is usually used when you have more than one job or pension. Here both salaries together stay in the 20% band, so a BR code on the second job deducts the right amount: £2,400.
Income Tax on the second job is the tax on both salaries together minus the tax on the main job alone. National Insurance is worked out on each job's pay separately in this calculation, so a second job paying under £12,570 a year pays none.
Figures use the 2026-27 rates for England: tax code 1257L with the £12,570 Personal Allowance, no other income and no student loan. Income Tax at 20% up to £50,270, 40% up to £125,140 and 45% above. The Personal Allowance falls by £1 for every £2 of income over £100,000. Employee Class 1 National Insurance is 8% on pay between £12,570 and £50,270 a year and 2% above.
Sources: Income Tax rates and allowances (GOV.UK), National Insurance: how much you pay (GOV.UK), Tax codes: overview (GOV.UK), What your tax code means (GOV.UK)