Only include genuinely self-employed locum days. PAYE shifts through an umbrella or practice payroll don't count towards this threshold.
If you work as a self-employed locum optician or optometrist, covering shifts across independent practices, multiples, or via a locum agency, Making Tax Digital applies to you the same way it applies to any self-employed sole trader. The detail that actually matters is working out which of your locum days are genuinely self-employed, since locum work is booked in several different ways that are taxed very differently.
Yes, if your gross genuinely self-employed locum income, plus any other self-employment or rental income, exceeds the relevant threshold:
| Tax Year Assessed | Threshold | MTD Start Date |
|---|---|---|
| 2024–25 | Over £50,000 | 6 April 2026. Live since April 2026 |
| 2025–26 | Over £30,000 | 6 April 2027 |
| 2026–27 | Over £20,000 | 6 April 2028 |
Your gross income is your total day-rate fees received before expenses, not your take-home after mileage, GOC fees or insurance. A locum working three to four days a week at a typical day rate can reach the £50,000 threshold comfortably across a full year.
Locum optical work is booked in several different ways, and only one of them counts towards your MTD threshold:
Whether you're booked through a locum agency or arrange shifts directly with practices makes no difference to your MTD position, provided the engagement itself is genuinely self-employed. What matters is the substance of the arrangement (are you invoicing for your services, controlling your own hours and using your own indemnity cover), not which route the booking came through.
| Expense Category | Examples |
|---|---|
| Professional registration | GOC annual retention fee |
| Professional indemnity insurance | Cover arranged independently or via a professional body |
| CET and CPD | Continuing education points required for GOC revalidation |
| Mileage | Travel between practices, at the current HMRC mileage rate |
| Equipment | Personal instruments not provided by the practice, via capital allowances if significant |
Sana's umbrella PAYE shifts are already taxed at source and excluded entirely. Only her £51,000 of genuinely self-employed bookings counts, which puts her just above the £50,000 Phase 1 threshold.
No. If an umbrella company employs you and deducts tax and National Insurance before paying you, that's employment income, not self-employment, and it doesn't count towards your MTD threshold regardless of how the booking was described.
The same as any self-employed sole trader: over £50,000 genuinely self-employed gross income in 2024–25 means MTD from April 2026, over £30,000 in 2025–26 means April 2027, over £20,000 in 2026–27 means April 2028.
No, provided the engagement itself is genuinely self-employed. The booking route doesn't change your tax position, what matters is whether you're invoicing for your services and controlling your own working arrangement, not the intermediary.
Yes. GOC registration fees, professional indemnity insurance, and CET or CPD course costs required for revalidation are all standard allowable expenses for a self-employed locum optician.
Check your remittance or booking confirmation. If tax and National Insurance are already deducted before you're paid, it's PAYE. If you're invoicing gross and responsible for your own tax, it's self-employed.
Any HMRC-recognised MTD software works. There's no optician-specific requirement, the main need is separating genuinely self-employed income from any umbrella PAYE shifts, which is a simple categorisation task in any standard software.
Our free calculator checks your exact threshold, deadlines, and recommends the easiest software for your record-keeping.
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