How is a second job taxed?

How a second job is taxed

You do not pay a special, higher tax on a second job. The difference is how your tax-free amount is used.

Everyone gets one Personal Allowance per tax year, however many jobs they have. For 2026/27 the standard Personal Allowance is £12,570. HMRC normally gives all of it to your main job, which is usually the one that pays most.

That means you pay tax on:

• your main job, but only on pay above your Personal Allowance
• all the pay from your other job or jobs, even if it is a small amount

The tax codes you might see

Your tax code tells your employer how much tax to take. These letters are common for a second job:

An S at the start means Scottish rates are used. A C means Welsh rates.

Worked example (2026/27)

You earn £8,000 a year in job 1 and £7,000 in job 2. Your Personal Allowance is £12,570.

• Total pay: £8,000 + £7,000 = £15,000
• Pay above your allowance: £15,000 minus £12,570 = £2,430
• Tax due for the year: £2,430 x 20% = £486

Here, job 1 does not use up all your allowance. If HMRC gave all the allowance to job 1 and put job 2 on BR, you would pay 20% on all £7,000 (£1,400). That is too much. This is why splitting matters.

Splitting your Personal Allowance

If your main job pays less than your Personal Allowance, you will not usually pay tax on it. The unused part of your allowance might be given to your other job, depending on your circumstances. Contact HMRC's Income Tax helpline to check if your allowance can be split.

National Insurance

You pay Class 1 National Insurance on earnings over £242 a week (2026/27). The main rate is 8%, and 2% on earnings over £967 a week.

If you earn £967 or more a week in one job and £242 or more in another, you may be able to defer (put off) some National Insurance. You then pay 2% instead of 8% in your other job. For 2026/27, HMRC must get your form CA72A by 14 February 2027. HMRC checks at the end of the year and writes if you owe anything.

Starting a second job

1. Give your new employer your P45, or fill in their starter checklist if you do not have one.
2. On the checklist, say that you have another job. If you do not, your tax code may be wrong.
3. Check your tax codes in your Personal Tax Account or the HMRC app. Your new job usually shows within 6 weeks of your first pay day.

If you are self-employed on the side

If you also earn more than £1,000 from self-employment in a tax year, you will usually need to register for Self Assessment. If it is £1,000 or less, you may not need to.

At the end of the tax year

After 5 April, HMRC checks your total income. If too much or too little tax was taken, it sends you a P800 tax calculation.

Related guides

• What does my tax code mean?
• What are the Income Tax rates?
• What is the Personal Allowance for 2026/27?
• How much National Insurance do I pay?
• What is a P45?
• Do you pay tax on tips?

Where this comes from

• How tax works if you have more than one job (GOV.UK)
• Tax codes: what your tax code means (GOV.UK)
• Tell HMRC if you have a new job or more than one job (GOV.UK)
• National Insurance: how much you pay (GOV.UK)
• Defer your National Insurance (GOV.UK)
• Income Tax rates and allowances (GOV.UK)