Sole traders
Income Tax and Class 4 National Insurance by tax year, with your expenses and mileage taken off.
Tax calculator for locums
Know your tax bill before HMRC does.
A running estimate of your Income Tax and National Insurance for the tax year, updated with every shift you book. Know what to put aside each month, and have your Self Assessment figures ready in January.
- 7-day free trial, no credit card required
- England, Scotland, Wales and Northern Ireland
- Cancel any time
Earnings
Projection for tax year 2026/27
- £8,603
- Projected Income Tax and NI
Set aside18%of each payment
| Total shift earnings | £48,600 |
| Less expenses and unpaid mileage | −£2,940 |
| Less personal allowance | −£12,570 |
| Income Tax at 20% | £6,618 |
| Class 4 National Insurance at 6% | £1,985 |
Figures are estimates to help you plan, not tax advice.
All year round
A tax estimate that keeps up with you.
Every shift you book, every expense you add and every mile you drive moves the estimate, so it's never more than a day out of date.
- Know what to set aside. Your projected bill for 6 April to 5 April, as a share of each payment, so it's in the savings account, not a surprise.
- Payments on account, foreseen. Your first January as a locum can mean a year's bill and half of the next. How payments on account work.
- Allowable expenses counted. Registration fees, indemnity, DBS, memberships and HMRC's mileage rate on travel the pharmacy didn't pay for. Edit them for each tax year.
- See which work is worth it. Your effective rate turns what you've earned into a full-time equivalent hourly rate, with trends over time.
Allowable expenses
Tax year 2026/27
| GPhC registration fee | £310 |
| Professional indemnity insurance | £193 |
| DBS Update Service | £16 |
| Professional body membership | £220 |
| Mileage the pharmacy didn't pay, 4,002 mi at 55p | £2,201 |
| Total | £2,940 |
Self Assessment
January's figures, ready in a click.
When the tax year ends, everything your Self Assessment needs is already added up and laid out the way the form asks for it.
- Laid out like the form. Your turnover, allowable expenses by category, travel, and profit, ready to copy into the self-employment pages.
- Reports for your accountant. Export any tax year as a PDF, with every shift, invoice and expense behind the totals.
- Every past year kept. Look back at any tax year's figures, and compare your earnings year on year.
- Looks ahead, not just back. Shifts you've booked but not yet worked are counted in the projection, so the estimate covers the whole tax year.
Self Assessment
Self-employment, tax year 2025/26
| Turnover | £44,210 |
| Car, van and travel expenses | £2,138 |
| Other allowable business expenses | £714 |
| Net profit | £41,358 |
- 191 shifts, 191 invoices, all paid
- 4,751 business miles at 45p
However you trade
Tax figures for every kind of locum.
Limited companies
Corporation tax by accounting period, and your salary, dividends and take-home by tax year. For limited companies.
Pharmacy technicians
The same running estimate, on your own earnings and expenses. For technicians.
Wherever you live
Bands for England, Wales and Northern Ireland, and a rougher guide in Scotland. Across the UK.
Drivers
Mileage at HMRC's rate for each tax year, worked out from your shifts. See the mileage tracker.
What changed this year
What the Budget means for you, in our guide to the Autumn Budget 2026.
Questions, answered.
How much tax should a locum set aside?
It depends on your profit, not your earnings, so there's no single answer. Locumoid works out your Income Tax and Class 4 National Insurance from your shifts, expenses and mileage, and shows it as a percentage of each payment to put aside. Many locums find it's between 15% and 25%.
Is the estimate tax advice?
No. The estimate uses current UK Income Tax bands and National Insurance rates for self-employed locums, so you know roughly what to set aside. It can't see your other income or personal circumstances, so check your Self Assessment with HMRC or an accountant.
Does Locumoid file my Self Assessment or Making Tax Digital updates?
No. It doesn't send anything to HMRC. It lays out the totals the way the Self Assessment form asks for them, ready for you or your accountant to copy. If Making Tax Digital for Income Tax applies to you, your MTD-compatible software does the sending, with Locumoid's figures to hand.
Does it work out payments on account?
Yes. If your bill is over £1,000, HMRC usually asks for half of next year's in advance, in January and July, on top of this year's. Locumoid shows them in your projection, so the first January as a locum isn't a shock. Our guide to payments on account explains how they work.
I live in Scotland. Is it accurate for me?
Treat it as a rougher guide. The estimate uses the Income Tax bands for England, Wales and Northern Ireland, and Scotland's bands differ. National Insurance is the same everywhere.
I have a limited company. Does it work for me?
Yes. Your company's profit and corporation tax are worked out by accounting period, and your personal tax on salary and dividends by tax year, with a switch between the two on the Earnings screen.
Keep exploring.
Mileage tracker
Business miles worked out from the real route for every shift, on the invoice and in your tax figures.
Locums with a limited company
Invoices from your company, corporation tax by accounting period, and your salary, dividends and take-home by tax year.
Going locum
Newly qualified or leaving employment? Set up your registration, indemnity, invoices and tax right from your first shift.
Stop dreading January.
Let Locumoid keep a running tax estimate from your shifts, so you know what to set aside long before the bill arrives.
7 days free · No credit card required · Cancel any time