Your income after tax and National Insurance as a self-employed associate — and the monthly percentage to set aside so January is a non-event.
Your share of fees, after lab deductions — the amount the practices actually pay you over a year.
GDC, indemnity, courses, equipment and so on — see our expenses guide if unsure.
From your pay statements. Leave at 0 if fully private.
Illustrative figures using 2026/27 rates and simplified assumptions — not advice, and no substitute for a proper calculation on your real numbers. Ask us for the accurate version — it's free.
The set-aside percentage is the number that matters day to day: move that share of every practice payment into a separate account and your tax bills are already funded. Remember your first-ever bill includes a 50% advance for the following year — our associate tax guide explains payments on account.
Everything here runs on 2026/27 figures. Income tax takes a £12,570 personal allowance, which tapers away by £1 for every £2 of income over £100,000 and is gone entirely by £125,140. The basic rate band is £37,700, so 40% starts at £50,270 and 45% at £125,140. Class 4 National Insurance is 6% on profits between £12,570 and £50,270, then 2% above that. Superannuation is deducted before tax, which is how the NHS net pay arrangement actually works — put your real figure in and the tax falls accordingly.
Take the default figures: £90,000 of associate income, £3,000 of expenses, fully private so no superannuation. Profit is £87,000. Income tax is £22,232 — the first £12,570 free, £37,700 at 20% and the remaining £36,730 at 40%. Class 4 adds £2,997: 6% on £37,700 and 2% on the £36,730 above the upper threshold. Take-home lands at £61,771, or £5,148 a month, and the suggested set-aside is 31% of everything the practices pay you.
That 31% carries a deliberate cushion of a couple of points above the arithmetic. Associates who set aside the exact figure tend to be caught out by a good year, because payments on account are based on the year before.
The figure above is a year's tax. Your first ever bill is not. On that same £87,000 of profit the tax and National Insurance come to £25,229 — but on 31 January you also pay the first payment on account for the following year, at half that again. The cheque is £37,843, not £25,229, and it is due in the same month as the return.
Nothing has gone wrong when that happens; it is the system catching up with a year of untaxed income. The following 31 July brings the second payment on account, and from then on the pattern settles into two instalments a year. Associates who have set money aside monthly since their first pay statement barely notice it. Associates who have not tend to remember it for a long time.
Student loan repayments, the High Income Child Benefit Charge, pension annual allowance charges, Scottish rates of income tax, and any year in which your profits jump enough to make payments on account bite hard. It also assumes a full tax year of trading. If you started mid-year, went part-time, or have employment income alongside associate work, the real number moves — often by more than people expect. Our expenses guide covers what legitimately reduces the profit figure at the top of this page.
These tools use sensible simplifications. A free conversation gets you the real calculation — and usually a couple of things worth fixing.
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