Year-end tax checklist for UK self-employed locums (running up to 5 April 2027)

5 April 2027 closes the 2026/27 UK tax year. Between now and then there is a short list of actions that can materially reduce what you owe in January 2028. Run through it. Most items take under an hour.

Six months before (early October 2026)

Reconcile your expense records. Go through Sessional, your spreadsheet, or your accounting software from April onward. Categorise every expense. Chase receipts you forgot to upload. By October you still have time to reconstruct; by March you will not.

Run a provisional tax estimate. Use our tax calculator with your year-to-date figures, extrapolated to April. Know roughly what January's balancing payment and payment on account will be.

Check the 25% rule has held. The tax-savings account should have roughly 25% of gross turnover in it (more if you are over £80,000). If it is lower, the December-to-January period is when to start putting more aside.

Three months before (early January 2027)

Submit your 2025/26 Self Assessment by 31 January 2027 (if you have not already). This is the previous tax year's return. File online through HMRC or your accountant.

Pay your 2025/26 balancing payment and first 2026/27 payment on account by 31 January. These are the two payments that trip up underfunded locums. Together they can be 1.5 times your actual tax bill for the year, because you are paying last year plus half of the current year.

Review this year's figures so far. With three months left, are you heading to £50,270, £100,000, or £125,140? Each threshold matters.

Two months before (early February 2027)

Consider a pension contribution. A SIPP contribution by 5 April reduces taxable profit pound-for-pound up to the annual allowance (£60,000 for most people; lower for very high earners). If you are near a band threshold, the saving is at your marginal rate, 40% or 45% for most higher earners. A £10,000 pension contribution at a 40% marginal rate saves £4,000.

Check tier for NHS pension if applicable. If your GP projected income bracket changed through the year, update the Form B tier before year end.

Run the limited-company-vs-sole-trader check. If you might incorporate for 2027/28, the setup takes 2–4 weeks. Start now for a 6 April start.

One month before (early March 2027)

Pay outstanding invoices owed to you. Pay your suppliers. Both sides: cash-basis accounting (what most sole traders use) means income is taxable when received and expenses are deductible when paid. Timing matters.

Make any substantial equipment purchases. New computer, clinical equipment, home-office furniture: buy before 5 April if you will use it for business. You either expense it or claim capital allowances.

Confirm all Form A documents are received. For GPs, every pensionable session needs a completed Form A. March is your last reasonable window to chase missing ones before the year closes.

In the last week before 5 April

Finalise mileage log. Total your business miles for the year. Keep it clean.

Pay any voluntary Class 2 National Insurance if you want to preserve qualifying years. At £3.65 per week × 52 = £189.80 for the year. Cheap insurance against a reduced state pension.

Record your opening balances for 2027/28. Note business bank account balance, outstanding invoices, debts owed.

After 6 April 2027

Start a 2026/27 tax return immediately if you can, even if you do not file until October. Fresh memory beats reconstruction every time.

Start tracking 2027/28 from day one. Carry over the 25% rule. Log every session as it happens. Upload receipts weekly.

What you cannot do after 5 April

• Change the amount of profit in 2026/27. The year is closed.
• Backdate a pension contribution to 2026/27 from 2027/28 money.
• Claim a business expense paid in 2027/28 against 2026/27 profit (under cash basis).
• Swap to a limited company structure for the already-closed year.

Keep records for six years

HMRC can investigate up to four years back normally, six years if they suspect underpayment, twenty years for deliberate avoidance. Keep receipts, invoices, bank statements, and tax returns for at least six years after the tax-year end.

Sessional keeps everything per tax year with unchanging records. The pre-year-end export is a single click. See our earnings dashboard for the overview and tax calculator for the projection.

For information only, not regulated advice. Check with a qualified accountant or adviser.