Tax set-aside calculator
The scariest question in self-employment is "how much of this money is actually mine?" This gives you a working answer: a percentage to move into a separate account every time a client pays, so the tax bill turns up already funded. It's a rough guide, not tax advice, and nothing you type is saved or sent anywhere.
Your income
Every time you get paid, move
27% to a separate account
- Set aside per month
- £1,350.00
- Yours to spend per month
- £3,650.00
- Tax pot after a year
- £16,200.00
The trick is doing it the day the money lands, not the week the bill does. If the pot ends up bigger than the bill, that's a bonus, not a problem.
Track what every client owes you for freeSole trader tax and NI, 2026/27
| Rate | |
|---|---|
| Personal allowance | £12,570 (no tax below this) |
| Income tax, basic rate | 20% to £50,270 |
| Income tax, higher rate | 40% to £125,140 |
| Income tax, additional rate | 45% above £125,140 |
| Class 4 NI | 6% on profits £12,570–£50,270 |
| Class 4 NI, above the upper limit | 2% |
The personal allowance is frozen at £12,570 until 5 April 2031, so as your profits rise more of them get taxed each year even though the rates never change.
Class 2 NI stopped being mandatory in April 2024. If your profits are above the Small Profits Threshold (£7,105 in 2026/27) your NI record is credited automatically. Below it, voluntary Class 2 at £3.65 a week protects your State Pension. For most people, worth paying.
Scotland is different. Scottish income tax has its own bands and rates, set by the Scottish Parliament rather than Westminster. National Insurance is the same UK-wide. If you're Scottish-resident, check your bands against gov.uk before you rely on a figure here.
The rule of thumb: set aside 30%
On profits under £50,270you're looking at roughly 26% combined (20% income tax plus 6% Class 4 NI) on everything above the allowance.
Setting aside 30% of profit gives you a margin for error and a small cushion for the year a good run pushes part of your profit into higher rate. The people who get caught out are the ones who set aside nothing in year one, because there was no payment on account yet, and then met two tax bills at once in January.
Setting money aside is easier when you know what you have actually been paid. SoloDesks tracks which invoices are settled and which have gone quiet. Start free.
Rates and thresholds for the 2026/27 tax year, rest of UK. General guidance only, not tax advice. Confirm anything you act on with gov.uk or your accountant before you rely on it.
Last checked: 30 July 2026
Common questions
- How much should I set aside for tax when self-employed?
- A common rule of thumb is 25% to 30% of your profit, moved to a separate account every time a client pays you. The right number depends on your country, your profit level and your deductions, so treat the percentage as a starting point and confirm it with an accountant after your first year.
- Should I open a separate account for tax money?
- Yes. A second free bank account is the single best tax habit for a solo business. Money you can see gets spent. Move the percentage the day a payment lands, and the tax bill becomes a transfer instead of a crisis.
- What happens if I set aside too much?
- Nothing bad. After the bill is paid, whatever is left in the pot is yours: an instant emergency fund, a van repair buffer, or a January that doesn't hurt. Aim high on purpose.
Next, in what you owe
Tax, VAT and CIS: the money that was never really yours to spend.
VAT calculator
Add VAT to a price or find the VAT hidden inside a total. Net, VAT and gross laid out clearly, at 20%, 5% or any rate.
CIS deduction calculator
Working under CIS? See what the contractor holds back from your labour and what actually lands in your bank.
Pricing the job
Work out what the job should cost before you write the number down.
Getting paid
Raise it, send it, and chase it when it goes quiet.
All nine are on the free tools page, and none of them need an account.