A Plain Guide to Accounting for Tradespeople
“Would highly recommend David. Professional, understanding and made the whole process straightforward, explaining every step.”
If you are a plumber, electrician, builder or any other tradesperson running your own business, keeping on top of the finances is probably the part of the job you like least. This guide covers what records you actually need to keep, which expenses you can claim, how VAT and CIS work in practice, and what to do if you have fallen behind.
Why accounting matters when you work in the trades
Running a trade business means your income can be irregular, your expenses are varied, and the tax rules that apply to you are more specific than they are for most other self-employed people. Getting this wrong does not just mean a penalty fine. It means paying more tax than you legally owe, or less than you should, both of which create problems with HMRC.
If you work in construction, roofing, electrical or plumbing, the Construction Industry Scheme may also apply to you. CIS adds a layer of compliance on top of standard self assessment requirements, and from 6 April 2026 mainstream contractors must file nil CIS returns even in months when no subcontractor payments are made. Missing that obligation carries penalties.
HMRC requires you to notify them by 5 October if you need to file a self assessment tax return for the previous year and have not done so before. Miss that date and you risk a fine before you have even filed anything. Your tax bill for the year is then due by 31 January. Source: GOV.UK Self Assessment overview.
Where most tradespeople go wrong with their accounts
The problems that come up most often are not complicated. They are things that build up gradually because there was always a more pressing job to get to. By the time they become urgent, they are harder to fix than they would have been if caught earlier.
Mixing personal and business money
Running personal and business transactions through the same bank account makes it very difficult to know your actual profit, claim the right expenses, or produce accurate records for HMRC. A separate business account does not need to be anything fancy. It just needs to exist so that your income and outgoings are traceable without guesswork.
Underestimating how much tax to set aside
Many tradespeople get a shock when their first self assessment bill arrives because nothing was put aside during the year. As a rough starting point, setting aside around 25 to 30 percent of your profit each month for income tax and National Insurance is a sensible habit, though your actual liability depends on your earnings, allowable deductions, and whether HMRC has asked for payments on account. Working this out properly at the start of the year, rather than at the end, avoids the kind of cash flow crisis that catches a lot of newly self-employed people off guard.
“Most tradespeople I speak to have not done anything catastrophically wrong. They have just let things pile up. In almost every case, it is fixable and it takes a lot less time than they expect once we sit down and go through it together. – David Roseweir, STZ Accounting”
What to do: a practical step-by-step approach
You do not need sophisticated software or a filing system built by someone from an office background. You need a consistent habit, a clear record of what comes in and goes out, and an accountant who can take it from there. Here is a straightforward way to approach it.
- Step 1: Open a dedicated business bank account. Every invoice you raise gets paid into it. Every business expense comes out of it. This one action removes about 70 percent of the confusion when it comes to year-end accounts or a self assessment return.
- Step 2: Keep receipts and invoices for everything. Tools, materials, fuel, work clothing, phone bills, van insurance and CIS subcontractor costs are all potentially allowable expenses. HMRC expects you to hold these records for at least five years after the 31 January submission deadline for that tax year. A photo on your phone using a free app like Dext or even a clearly labelled folder on cloud storage is enough to start.
- Step 3: Register for self assessment as soon as you start trading, and register for VAT if your turnover reaches or is likely to reach the current threshold within any 12-month period. If you work in construction and pay subcontractors, you will also need to register as a CIS contractor. Missing these registration points is one of the most common sources of avoidable penalties. The official HMRC CIS guidance (CIS 340) sets out exactly what is required.
Once these foundations are in place, the day-to-day work becomes much more manageable. You are not trying to run an accounting department. You are just keeping a clean trail of what happened so that filing is straightforward when the deadline arrives.
What does accounting actually cost for a tradesperson?
The honest answer is that the cost of getting it right is almost always lower than the cost of getting it wrong. A penalty for a late self assessment return starts at £100 and increases the longer it remains unfiled. Missing VAT registration obligations, failing to operate CIS correctly, or claiming expenses that cannot be substantiated all carry their own risk of fines and interest. At STZ Accounting, sole trader packages start from £150 per month plus VAT and cover bookkeeping, bank reconciliation, VAT returns, annual accounts and a personal self assessment return. You get a fixed price agreed upfront, with no surprises.
| Option | Pros | Cons |
|---|---|---|
| DIY accounting | No accountancy fee | High risk of missed deadlines, unclaimed expenses and penalties |
| Using an accountant | Accurate returns, all allowances claimed, HMRC compliance handled for you | Monthly or annual fee, which is itself a tax-deductible expense |
How to get this sorted today
If you have been putting this off, the most useful thing you can do is to take one concrete step today rather than waiting until January. Whether your records are in good shape or you have a carrier bag of receipts going back two years, David works with tradespeople at every stage and will tell you plainly what needs to happen and what it will cost.
- Gather your bank statements and any receipts you have for the current tax year and note down which months you are missing. That is the starting point for any catch-up work.
- Book a free 20-minute call with David at stzaccounting.co.uk/discovery-call. You will leave the call knowing exactly what needs to be done, in what order, and what it will cost.
Ready to sort your trade business accounts?
David handles self assessment returns, bookkeeping, VAT, CIS returns and year-end accounts for tradespeople across the UK, all at a fixed price agreed before any work starts. There is no tie-in contract and you always deal with David directly.
How in order are your business records right now?
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AAT qualified accountant based in Strathaven. Personal, one-to-one accounting for small businesses and sole traders across the UK.
