Key Tax Dates for Locum GPs
All the HMRC deadlines that matter for self-employed GPs — with a live countdown to the next one.
Self Assessment Deadlines
Jan
Two amounts due on the same day:
- Balancing payment — the remaining tax owed for the year just ended (actual liability minus any payments on account already made)
- First Payment on Account — 50% of this year's estimated liability, towards the next tax year
For new locums: your first January bill is typically 1.5× your annual tax liability. Budget from day one.
Full guide to Payments on Account →Jul
The second instalment — again 50% of last year's Self Assessment liability. Together with the January payment, these two instalments pre-pay your estimated tax for the current year.
If your income is lower this year, you can apply to reduce this payment via SA303 or your HMRC online account.
Feb
If you did locum sessions within the NHS Pension scheme during the previous tax year, your SD55 (Locum A/B) form must be submitted to the NHS Business Services Authority by 28 February. Missing this deadline can permanently forfeit that year's NHS pension contributions — there is no late-submission route.
Your SD55 must be countersigned by the practice. Chase it in January if you haven't received confirmation.
NHS Pension SD55 guide →Oct
If you started locuming in the 2024/25 tax year and haven't yet registered for Self Assessment, you must do so by 5 October 2025. Failure to register on time risks a £100 late-filing penalty — even if no tax is owed.
Register at gov.uk/register-for-self-assessment. Takes 10 minutes.
Making Tax Digital (MTD) Quarterly Deadlines
Self-employed GPs earning over £50,000 must submit quarterly digital updates to HMRC from 6 April 2026. If your income is £30,000–£50,000, the April 2027 start date applies.
Quarterly submission deadlines (from April 2026):
Quick Reference — All Annual Dates
| Date | What's due | Who |
|---|---|---|
| 31 January | Balancing payment + 1st Payment on Account + online Self Assessment return | All self-employed locums |
| 28 February | NHS Pension SD55 (Locum A/B form) submission deadline — missing this permanently forfeits that year's pension contributions | NHS pension locums |
| 31 July | 2nd Payment on Account | Where liability ≥ £1,000 |
| 5 October | Register for Self Assessment (new self-employed only) | First year locums |
| 31 October | Paper Self Assessment return deadline (if filing by post) | Paper filers only |
| 6 Apr / 6 Jul / 6 Oct / 6 Jan | MTD quarterly update periods begin (from April 2026) | Income > £50k from April 2026 |
Estimate your January bill now
Use the calculator to see your estimated income tax, NI, and Payments on Account for 2025/26.
Open Tax Calculator →Dates are for the 2025/26 tax year (England & Wales). Confirm deadlines at gov.uk. Not financial or legal advice.