23 June 2026 · 5 min read · Bruce Thomas
In the first year of self-employment, with modest income and simple records, a careful person with good software can file their own return. There is no shame in doing so and no requirement to appoint anyone.
But there are identifiable points at which doing it alone starts costing more than it saves.
Triggers worth acting on
- Turnover approaching the VAT registration threshold
- Taking on your first employee or subcontractor
- Buying a vehicle, plant or significant equipment
- Working under CIS and having deductions taken at source
- Adding rental income, dividends or capital gains to your return
- Profit reaching a level where a limited company might be more efficient
- Spending more than a couple of hours a week on paperwork
The reliefs people miss
Use of home, mileage, capital allowances on equipment, pension relief and, where relevant, the marriage allowance are all routinely underclaimed on self-prepared returns. Individually they are small; over several years they are not.
Equally common is the opposite problem — claiming something that is not allowable, which creates a risk rather than a saving.
The cash flow benefit
Knowing your tax bill in July rather than mid-January changes how the autumn feels. It also means the payment on account is planned for rather than discovered.
If you are a CIS subcontractor with deductions to reclaim, filing early after 6 April usually means the refund arrives months sooner.
What it should cost
For a straightforward sole trader, the fee should be modest and fixed. If it is not obvious that the advice and the time saved cover it, say so — a good accountant will tell you honestly if you do not need them yet.
This article is general guidance for business owners in the UK and does not amount to advice for your particular circumstances. Tax rules change and the right answer depends on your figures — please take specific advice before acting.
