Starting a Personal Training Business
Written and reviewed by the Personal Trainer Accountants editorial team. Last reviewed 8 August 2026.
The first year is the one where decisions are cheapest to get right and most expensive to fix later. Almost none of it is complicated.
This is the administrative side. It is not a business plan and it is not marketing advice, both of which you can get better elsewhere.
Registering as Self-Employed
Register with HMRC once your gross self-employed income passes £1,000 in a tax year, and no later than 5 October after the end of that year. Below £1,000 the trading allowance generally covers you, though claiming it means you cannot deduct expenses, which can be the wrong choice in a first year with heavy set-up costs.
Registering early costs nothing and removes a deadline from the list. There is more detail on the self-employed trainer page.
Records From Day One
Two habits make everything afterwards easier. Keep business money separate from personal money, even if that is just a second current account rather than a business account. And log business mileage as you drive it, because at 55p a mile for the first 10,000 miles it is likely to be one of your largest single deductions and it is the one nobody can reconstruct honestly at year end.
Keep receipts for equipment, insurance, gym rent, CPD, software and your phone bills. Photographs of receipts are fine. The standard to aim at is that someone else could follow your figures back to a document, because that is exactly what a compliance check asks for.
If you expect to pass £50,000 of qualifying income, get onto proper software early. Making Tax Digital already applies at that level and quarterly updates are much less painful when the records were digital from the start.
Insurance and Qualifications
Public liability and professional indemnity insurance are normal for the trade and both are allowable business expenses. Gyms and most insurers will expect a recognised qualification, and many trainers hold membership of a professional body, which is also an allowable cost.
We are not authorised to advise on insurance and will not recommend a policy or a provider. On the professional standards side, CIMSPA is the professional development body for the UK sport and physical activity sector and is the sensible starting point for what the sector expects.
The First Tax Year
The first bill is usually bigger than expected, for two reasons that have nothing to do with doing anything wrong. It combines income tax with Class 4 National Insurance at 6% on profits over £12,570. And if the bill is large enough, HMRC also asks for a payment on account towards the following year at the same time, which can feel like being charged twice.
Set money aside from the start as a percentage of what comes in rather than trying to find it in January. The deadlines are 31 January for filing and paying, with the second payment on account on 31 July, and the filing penalty is automatic. HMRC sets out the trading allowance and registration rules in its tax-free allowances guidance.