Most tradespeople are good at their trade and completely unprepared for what HMRC expects from their business. This guide explains the core accounting obligations for sole traders and limited companies in the trades, including self assessment, VAT, CIS, and what to do if you have fallen behind.

Why accounting for tradespeople is different from other businesses

Tradespeople face a combination of accounting obligations that most other small businesses do not. If you work in construction, you are likely affected by the Construction Industry Scheme. If your turnover is above the VAT threshold, you have to register, choose the right scheme, and file returns on time. Add in self assessment or corporation tax, and the paperwork builds fast.

The practical reality of the trades makes this harder. You buy materials on the spot, sometimes get paid in cash, use a personal card for business purchases, and quote jobs that end up costing more than expected. None of that is unusual. It does mean your records need to be clear enough to separate what is a business expense from what is not.

Where most tradespeople go wrong with their accounts

The most common problems I see are not caused by dishonesty or laziness. They come from a lack of a system. When there is no regular process for recording income and expenses, the gap between what you think you have earned and what you actually owe in tax can be significant.

Not tracking CIS deductions properly

If you work as a subcontractor, a contractor will deduct 20% from your labour payments under the Construction Industry Scheme and pass that to HMRC. That money is a payment on account of your tax bill, not a loss. If you do not track those deductions carefully, you cannot reclaim them correctly on your self assessment return. From April 2021, HMRC gained new powers to amend CIS deduction claims on RTI returns where they identify errors or omissions, so accuracy matters more than ever. From 6 April 2026, new fraud measures allow HMRC to cancel gross payment status, recover lost tax and apply penalties of up to 30% to businesses and their directors personally.

Mixing business and personal finances

Using a personal bank account for business transactions is one of the most common reasons tradesperson accounts take longer to prepare and cost more to sort out. Every transaction needs to be reviewed individually to work out what is business and what is personal. A separate business account takes ten minutes to open and saves a significant amount of time and money at year-end.

What to do with your accounts, step by step

You do not need to master accounting. You need a reliable process that means nothing slips through the cracks. The steps below cover the core obligations for most tradespeople operating as sole traders or limited companies.

1. Record every transaction as it happens. This means income received, materials purchased, fuel, tools, and any subcontractor payments you make. A cloud accounting tool like QuickBooks or FreeAgent makes this straightforward on your phone. The goal is a complete record at all times, not a shoebox to sort through in January.
2. Know your VAT position. If your taxable turnover is above £90,000, VAT registration is compulsory. Once registered, you need to file quarterly VAT returns under Making Tax Digital, which means using compatible software. Check whether the Flat Rate Scheme is worth using for your trade type, given the rates set by HMRC vary considerably depending on how much of your work is labour versus materials.
3. File your tax return on time. Sole traders file a self assessment return by 31 January each year. Limited companies file accounts with Companies House and a corporation tax return with HMRC within nine months of the year-end. If you are in the Construction Industry Scheme as a contractor, you also need to submit monthly CIS returns to HMRC, including a nil return in any month where no subcontractors were paid.

If you run your own subcontractors, you take on a contractor’s responsibilities under CIS. That means verifying subcontractors with HMRC, deducting the correct amount, paying that to HMRC monthly, and issuing payment and deduction statements. From 6 April 2026, payments to local authorities and certain public bodies are exempt from CIS, which is a welcome simplification for those working with public sector clients.

Costs and what to expect

The real cost of not having proper accounts is rarely obvious until something goes wrong. A missed CIS deduction claim, the wrong VAT flat rate, or a late self assessment return each carry their own financial consequences. The question is not whether to deal with your accounts but how much time and risk you are willing to carry by doing it alone.

How to get started today

If your records are behind, the worst thing you can do is wait longer. A short call is enough to work out exactly where things stand and what needs sorting first. The starting point is rarely as complicated as it feels from the outside.

• Open a dedicated business bank account if you do not already have one, and stop mixing personal and business transactions from today.
• Pull together your CIS deduction statements for the current tax year and check whether you have a record of every amount deducted. If you cannot find them, your contractor is obliged to provide them.