Tax on two jobs · 2026/27 tax year
Tax on self-employed side income alongside a job
If you have a job and earn extra from self-employment, such as dog walking or selling a service, the first £1,000 a year of that income is covered by the trading allowance. If the side income is £1,000 or less you usually do not need to tell HMRC. Above £1,000 you must register for Self Assessment and pay tax on the rest at your top rate: GOV.UK's example of £3,500 alongside a £22,000 job costs £500.
Second job tax rules checked against GOV.UK on .
Trading allowance
£1,000
a year, tax-free
Self Assessment
Over £1,000
of gross side income
Tax on £3,500 side income
£500
with a £30,000 job
Class 4 NI starts
£12,570
of self-employed profit
Side income on top of a £30,000 job, 2026/27
Income Tax on self-employed side income after the £1,000 trading allowance, with the job using your Personal Allowance. No expenses claimed.
| Side income a year | Self Assessment needed | Taxable after allowance | Extra Income Tax |
|---|---|---|---|
| £800 | Usually not | £0 | £0 |
| £1,000 | Usually not | £0 | £0 |
| £1,500 | Yes | £500 | £100 |
| £3,500 | Yes | £2,500 | £500 |
| £8,000 | Yes | £7,000 | £1,400 |
| £12,000 | Yes | £11,000 | £2,200 |
£3,500 of side income at different job salaries
The same side income is taxed at your top rate, so it costs more once your job pays over £50,270.
| Job pay | Tax on £3,500 side income | You keep |
|---|---|---|
| £22,000 | £500 | £3,000 |
| £30,000 | £500 | £3,000 |
| £50,000 | £946 | £2,554 |
| £60,000 | £1,000 | £2,500 |
Allowance or expenses, not both
GOV.UK says that if you claim the trading allowance you cannot deduct any other expenses. If your real costs are over £1,000, for example equipment and travel, you are usually better off deducting those instead.
Who cannot use it
The trading allowance does not cover income from your employer or your spouse's or civil partner's employer, from a partnership where you or someone connected to you is a partner, or from a company you or a connected person owns or controls. Extra shifts for your own employer are just more pay through PAYE.
Registering and paying
Register for Self Assessment by 5 October after the end of the tax year the income was earned in, so by 5 October 2027 for 2026/27 income. Your job's tax code still gives it your whole allowance, and the tax on your side income is paid through your return.
National Insurance on side income
Self-employed Class 4 NI is based on your self-employed profits alone, not added to your wages. It is 6% on profits over £12,570 a year, so a small side business usually pays none. With profits of £7,105 or more, GOV.UK says Class 2 is treated as paid.
A second employed job is different
If the extra work is a job with payslips, the employer takes tax through PAYE on a code like BR and you do not need Self Assessment for it. See the basic rate page or use the calculator for that case.
Guides and definitions
- Why is my tax code wrong? What it means and how to fix it (Guide)
- Emergency tax code (An emergency tax code, marked W1, M1 or X, taxes each payday on its own, as if you were paid that amount every period of the year.)
- Marginal tax rate (Your marginal tax rate is the share of your next pound or dollar of income that goes in tax and deductions.)
- P11D (A P11D is the form UK employers send HMRC by 6 July to report each employee's taxable benefits and expenses that were not taxed through payroll.)
- P60 (A P60 is the yearly summary of your pay and tax from one employer, due by 31 May if you work there on 5 April.)
- Personal Allowance (The Personal Allowance is the income you can earn each UK tax year before Income Tax starts: £12,570 for 2026/27.)
Other second job situations
- Second job on BR (basic rate) (Main job under £50,270: every pound of the second job taxed at 20%)
- Second job at 40% (D0) (When a second job takes you over £50,270)
- Splitting your allowance (Main job under £12,570: move the unused allowance)
- National Insurance on two jobs (Each job has its own NI threshold)
Second job tax: the overview · BR tax code explained · D0 tax code explained · Second job tax calculator · If your extra work is an employed job, check it here
Common questions
Do I pay tax on side income if I have a full-time job?
Yes, on anything above the £1,000 trading allowance. Your job normally uses your whole Personal Allowance, so side income over £1,000 is taxed at your top rate, usually 20% or 40%, through Self Assessment.
Do I need to tell HMRC about side income under £1,000?
Usually not. GOV.UK says you must register for Self Assessment if your gross trading income is over £1,000. At £1,000 or less the trading allowance covers it, though there are some exceptions, such as income from your own employer.
How much tax will I pay on £3,500 of side income?
With a £22,000 job, GOV.UK's example gives £500: the first £1,000 is tax-free and the other £2,500 is taxed at 20%. With a £60,000 job it would be £1,000, because the £2,500 is taxed at 40%.
Do I pay National Insurance on self-employed side income?
Only if your self-employed profits are over £12,570 a year, when Class 4 NI of 6% applies. It is based on those profits alone, not added to your wages, so most small side businesses pay no NI.
Can I claim the trading allowance and my expenses?
No. GOV.UK says you cannot deduct other expenses if you claim the allowance. Pick whichever is bigger: the flat £1,000, or your actual business costs.
Sources and assumptions
- Income Tax for the 2026/27 tax year (6 April 2026 to 5 April 2027), with the same pay every month from both jobs for the whole year.
- England, Wales and Northern Ireland rates unless a table says Scotland. The main job is on 1257L with the standard £12,570 allowance and pay under £100,000.
- Employee National Insurance is worked out on each job's monthly pay with HMRC's monthly thresholds (£1,048 and £4,189), so yearly totals can differ by a few pence from an annual sum.
- Side income is self-employed trading income with the £1,000 trading allowance claimed and no other expenses. Class 4 NI is not in the tables because all profits shown are under £12,570.
- GOV.UK: How tax works if you have more than one job
- GOV.UK: Tax codes, what your tax code means
- GOV.UK: Income Tax rates and Personal Allowances
- GOV.UK: Tax-free allowances on property and trading income
- GOV.UK: Register for Self Assessment
- GOV.UK: Self-employed National Insurance rates
- GOV.UK: Income Tax enquiries (HMRC contact)
These are estimates to help you understand tax on more than one job, not tax advice. HMRC and your employers' payroll decide what you actually pay.