Tax year 2026/27
The numbers HMRC actually uses
This is a map, not a personal tax return. Rates below are for England, Wales and Northern Ireland. Scotland has its own bands. Always check GOV.UK or a qualified accountant before you file.
Allowances that matter for a side hustle
| Allowance | 2026/27 | Applies to |
|---|---|---|
| Trading allowance | £1,000 | Gross self-employment and casual selling, one pot |
| Property allowance | £1,000 | Property income, separate from trading |
| Rent-a-Room relief | £7,500 | Furnished lodging in your only or main home |
| Personal Allowance | £12,570 | All income; tapers above £100,000 |
| Dividend allowance | £500 | If you take dividends from a company |
| Capital gains exempt amount | £3,000 | Gains on assets, not trading stock |
Income tax bands (England, Wales, NI): 20% on £12,571–£50,270, 40% on £50,271–£125,140, 45% above. Class 4 NIC is 6% on self-employed profits between £12,570 and £50,270, and 2% above. Class 2 is abolished for most sole traders.
Take-home sketch
A rough picture of tax on extra trading profit when you already use your Personal Allowance at work. It assumes you claim the £1,000 trading allowance rather than actual expenses, and that Class 4 NIC does not apply because profit stays under £12,570. It is not a tax calculation you can file.
Taxable after allowance
£4,000
Income tax on this
£800
You keep
£4,200
When you must tell HMRC
Register for Self Assessment by 5 October following the tax year in which your gross trading income went over £1,000. For 2026/27 that is 5 October 2027. The online return is then due by 31 January 2028, with tax paid the same day.
You also register if you want to claim a loss, if you are already in Self Assessment, or if other untaxed income requires a return. Selling your own old possessions does not, by itself, put you in Self Assessment.
Making Tax Digital
From April 2026, self-employed people and landlords with qualifying income over £50,000 need to keep digital records and send quarterly updates. The threshold falls in later years. Most evening side hustles will not hit that line in 2026/27. If you might, use software HMRC lists as compatible rather than a paper notebook.
Mileage: cars and vans 55p for the first 10,000 business miles in 2026/27, then 25p. Motorcycles 24p. Bicycles 20p. You cannot mix simplified mileage with claiming actual fuel on the same vehicle for the same year.
Not advice. cubidexa publishes general information about UK side income. It is not tax, legal or financial advice, and it is not a substitute for GOV.UK or a qualified adviser who can see your figures. Tax rules change. Check the date on the GOV.UK page before you rely on a number.