£18,000 + £12,000 Second Job Tax 2025-26
Income tax · National Insurance · Take-home pay on second job
Tax code on your second job: BR (20%)
Your first job of £18,000 uses up the personal allowance (£12,570), so your second job uses tax code BR — all earnings taxed at 20% basic rate.
£18,000 + £12,000 — full tax breakdown 2025-26
| Item | First job (£18,000) | Second job (£12,000) | Combined (£30,000) |
|---|---|---|---|
| Gross salary | £18,000 | £12,000 | £30,000 |
| Income Tax | -£1,086 | -£2,400 | -£3,486 |
| National Insurance | -£434 | -£0 | see note* |
| Take-home | £16,480 | £9,600 | £25,120 |
*NI is calculated per employer independently. Combined take-home shown uses each job's NI separately.
How is tax calculated on a £12,000 second job?
When you have two jobs, your Personal Allowance (£12,570 in 2025-26) is allocated to your main employment. Your second employer receives tax code BR (20%) from HMRC, meaning the second job's earnings are taxed from the first pound at your marginal rate.
On a £12,000 second job, you pay £2,400 income tax and £0 NI, leaving a take-home of £9,600. Your effective tax rate on the second job income is 20.0%.
National Insurance is handled separately by each employer — HMRC does not combine your earnings for NI purposes. Each employer applies the £12,570 NI Primary Threshold to their payroll independently. This generally means less NI on a smaller second job.
Frequently asked questions
How much tax do I pay on a £12,000 second job?
With a first job of £18,000, your personal allowance is already used. On your £12,000 second job you pay £2,400 income tax and £0 NI, leaving a take-home of £9,600. Your effective tax rate on the second job is 20.0%.
What tax code is used for a second job?
Your first job of £18,000 uses up the personal allowance (£12,570), so your second job uses tax code BR — all earnings taxed at 20% basic rate. HMRC issues this code automatically to your second employer. If your circumstances change, you can update it via your Personal Tax Account at gov.uk.
Is National Insurance calculated separately for each job?
Yes. Each employer operates their own PAYE payroll and applies the NI Primary Threshold (£12,570) independently. On a £12,000 second job, you pay £0 NI — much less than on a single combined salary, because the NI threshold applies separately to each employment.
Do I need to file a Self Assessment for two jobs?
You may need to file a Self Assessment if you have two or more sources of income and the combined amount means you owe tax not collected through PAYE. HMRC usually reconciles this automatically via a P800, but if your combined income exceeds £100,000, or you have untaxed income, you must register for Self Assessment by 5 October following the end of the tax year.