Can you be employed and self-employed at the same time?
Yes. You can have a PAYE job, where your employer takes tax from your pay, and run a business alongside it. Each type of income comes with its own admin, so keeping the two clearly separate makes life easier. GOV.UK: working for yourself.
Your Personal Allowance isn’t doubled
For Income Tax, your taxable business profit is looked at together with your employment income. You don’t get a new Personal Allowance, the amount of income you can have before you pay Income Tax, for the side business.
Suppose your taxable salary is £40,000 and your sole-trader taxable profit is £5,000 in 2026/27. With a standard Personal Allowance, no other income or adjustments, and England, Wales or Northern Ireland rates, the extra £5,000 falls within the 20% band. The extra Income Tax is £1,000. This example uses HMRC’s Income Tax rates.
The result can change with:
a different salary
Scottish tax bands
other income
Does a side hustle get its own low tax rate? It doesn’t.
National Insurance works differently
Class 1 NI on employment and Class 4 NI on self-employment are worked out differently. In the example above, £5,000 of business profit is below the £12,570 Class 4 threshold, so there’s no Class 4 charge on that profit.
If your combined earnings are higher, the way the different contribution classes interact may mean an adjustment is needed. Don’t just add two maximum charges together. HMRC: NI with employment and self-employment.
You may still need to register
Having a job doesn’t remove the obligation to report a business. Gross trading income above £1,000 normally means you need to register for Self Assessment. The trading allowance has exceptions, including relevant trading income from your employer. HMRC: trading allowance. If you later close the business and keep the job, see what to do when you stop being self-employed.
Keep records of business income and expenses alongside your employment paperwork. If student loan repayments are due, Self Assessment takes account of repayments already taken through payroll. So enter those details accurately. HMRC: student loan repayments.
Check the practical boundaries too
Read your employment contract for terms about outside work, confidentiality and conflicts of interest. Keep your employer’s time, equipment and information separate from your business, unless you have permission to use them.
When you budget, work out the extra tax the business creates, then set it aside as you go. The tax taken from your salary may be right for your job without covering the new income at all.
