What a bookkeeper costs a self-employed subcontractor in 2026/27
Trade-reported bookkeeping rates for a one-person construction business fall broadly between £15 and £45 per hour for a freelance bookkeeper, and roughly £25 to £60 per hour where the work sits inside an accountancy practice. On a fixed monthly package, most sole trader subcontractors with modest transaction volumes land somewhere between £40 and £150 per month.
Those figures are market observations rather than published prices. Bookkeeping is not a regulated service with a fee scale, so every quote is built from the specific job. What follows sets out what actually drives the number for a CIS subcontractor, where a bookkeeper stops and an accountant starts, the construction-specific records that make trade bookkeeping different from ordinary small business bookkeeping, and the point at which software does the same work for a fraction of the price.
| Arrangement | Typical reported range (2026) | Who it tends to suit |
|---|---|---|
| Freelance bookkeeper, hourly | £15 to £45 per hour | Low, irregular volume; catch-up work; seasonal trades |
| Practice-based bookkeeping, hourly | £25 to £60 per hour | Subcontractors who want bookkeeping and annual tax work under one roof |
| Fixed monthly package, sole trader | £40 to £150 per month | One or two contractors, a van, 30 to 60 receipts a month |
| Fixed monthly package with VAT returns | £90 to £250 per month | VAT-registered trades applying the domestic reverse charge |
| Accounting software only | £10 to £30 per month | Organised sole traders doing their own recording |
Ranges are indicative of the wider UK market and are not a quote. Regional variation is significant, and a bookkeeper who works regularly with construction clients will normally price above a generalist because the CIS work carries more steps.
What drives the price for a CIS subcontractor
Bookkeeping is priced on transaction volume and complexity, not on turnover. A subcontractor invoicing £70,000 to two main contractors with 30 purchase receipts a month is a cheaper job than one invoicing £45,000 across ten small jobs with materials bought daily from three merchants.
The variables that move the fee most:
- Number of transactions. Bank lines and receipts are the unit of work. Everything else follows from this.
- Whether you are VAT registered. Quarterly returns plus the domestic reverse charge decision on every invoice adds real time.
- Whether you pay anyone. Payroll, or paying your own subcontractors and filing CIS300 monthly returns, is a separate service and priced separately.
- How the records arrive. Receipts photographed weekly cost less to process than a year of paper delivered in January. Catch-up work is routinely quoted at a premium.
- Whether the bookkeeper knows CIS. Construction experience costs more per hour and normally saves money overall, for the reasons in the next section.
Bookkeeper versus CIS accountant: what you are actually buying
A bookkeeper records. An accountant interprets and files. Treating the two as substitutes is the fastest way to end up with a budget that leaves the annual work unpriced.
| Task | Bookkeeper | CIS accountant |
|---|---|---|
| Categorising bank transactions and receipts | Yes | Usually, at a higher rate |
| Recording the labour and materials split on invoices | Yes, if CIS-literate | Yes |
| Matching contractor deduction statements to payments | Yes, if CIS-literate | Yes |
| Preparing and filing Self Assessment | Rarely, and often outside scope | Yes |
| Preparing the CIS refund claim | No | Yes |
| Gross Payment Status application and maintenance | No | Yes |
| Company accounts and corporation tax return | No | Yes |
| Advice on sole trader versus limited company | No | Yes |
The practical consequence is that a bookkeeper's £80 per month is not comparable to an accountant's £80 per month. For what specialist annual and compliance work involves, and the fee benchmarks that go with it, see our guide to what a CIS accountant does and whether you need one. If you are weighing up structure at the same time, our comparison of CIS as a sole trader or a limited company covers how the recovery route and the compliance load differ.
The CIS records that make trade bookkeeping different
Ordinary small business bookkeeping records money in and money out. Construction bookkeeping has three extra obligations that a generalist will often miss, and each one has a direct cost if it goes wrong.
The labour and materials split on every invoice. CIS deductions apply to the labour element of a payment only. Materials are excluded from the deduction base. A £1,000 invoice made up of £600 labour and £400 materials carries a 20% deduction of £120, not £200. If your books do not carry that split, you cannot check whether a contractor deducted correctly, and overdeductions go unnoticed.
Gross recording, not net. A contractor pays you the net figure after deduction. If the books record only what hit the bank, your turnover is understated by the whole of the CIS deducted and the deduction itself disappears from the record. The correct treatment is to record the gross invoice, the deduction as a separate item, and reconcile down to the net receipt.
Payment and deduction statements matched to payments. Contractors must give you a statement for each tax month in which they deducted. Those statements are the evidence base for the refund. Filing them as they arrive, and matching each one to the payment it relates to, is a monthly bookkeeping task, not a January archaeology exercise. Our CIS record-keeping guide sets out the full document set and the retention periods.
Alongside those, the ordinary expense discipline still applies: a contemporaneous mileage log, now at 55p per mile for the first 10,000 business miles from 6 April 2026 and 25p thereafter, plus receipts for tools, PPE and materials. Our guide to allowable expenses for CIS subcontractors covers what qualifies.
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When software beats paying a subcontractor bookkeeper
For a large share of sole trader subcontractors, CIS-aware accounting software at roughly £10 to £30 per month does what a bookkeeper would be doing by hand: bank feeds, receipt capture from a phone, mileage tracking, and invoices that split labour and materials and calculate the deduction for you.
Software is usually the better value option when all of the following hold:
- You invoice a small number of regular contractors rather than many one-off clients
- You are not VAT registered, or your VAT position is simple
- You do not pay your own subcontractors
- You are willing to spend 30 minutes a week on it rather than letting it pile up
Paying someone starts to win when the volume climbs, when the domestic reverse charge starts applying to your invoices, when you take on CIS300 monthly filing for your own subcontractors, or simply when the hours you spend on records exceed what you could bill in the same time. A subcontractor on a £250 day rate spending five hours a month on paperwork is spending roughly £150 of billable capacity to avoid a fee that may be lower than that.
What software does not do is the annual tax work. It produces the records; it does not prepare the Self Assessment return, calculate the position, or build and file the refund claim. That remains a separate job whichever way you handle the day to day.
How MTD for Income Tax changes the maths
From 6 April 2026, sole traders and landlords with qualifying income over £50,000 must keep digital records and send quarterly updates under Making Tax Digital for Income Tax. The threshold drops to £30,000 from 6 April 2027 and to £20,000 from 6 April 2028, which brings almost every full-time subcontractor into scope within the next two years.
Two points matter for the bookkeeping decision. First, qualifying income for a CIS subcontractor is gross turnover before deductions, not the net figure that reaches your bank. A subcontractor banking £48,000 after 20% deductions on £60,000 gross is tested on the £60,000 and is in scope. Second, MTD converts bookkeeping from an annual catch-up into a quarterly rhythm, which removes the option of doing nothing until January. Full detail is in our guide to MTD for Income Tax and CIS.
Practically, that means the choice is no longer between paying a bookkeeper and doing nothing. It is between paying a bookkeeper and maintaining compliant digital records yourself with software. The cost gap narrows once the software subscription is a requirement rather than an option.
Worked comparison: annual cost for a sole trader subcontractor
A sole trader groundworker with £62,000 gross CIS income, two main contractors, no VAT registration and around 45 receipts a month, on 2026/27 figures:
| Approach | Indicative annual cost | What is still outstanding |
|---|---|---|
| Software only, records kept weekly | £180 to £360 | Self Assessment, refund claim, quarterly MTD submissions |
| Software plus monthly bookkeeper | £780 to £2,160 | Self Assessment and refund claim |
| Annual catch-up bookkeeping in January | £400 to £900 plus premium for disorder | Self Assessment, refund claim, MTD non-compliance risk |
Figures are illustrative combinations of the market ranges above, not quotes. The column that matters most is the third one. Bookkeeping cost is only half the budget, and the half that recovers the overpaid deductions is the other half. Because bookkeeping and accountancy fees are themselves allowable expenses, a basic-rate sole trader carries roughly 71p of every £1 of fee after income tax and Class 4 National Insurance relief.
To see what the deductions side of that picture looks like before you commit to any arrangement, run your income and deduction figures through our CIS refund estimator.
Bookkeeping for a self-employed tradesperson is priced by volume and complexity, and for most sole trader subcontractors the honest answer is £40 to £150 a month for a fixed package, less if software and a weekly habit cover the recording. The construction-specific point is that whoever keeps your books must record gross invoices, the labour and materials split, and every contractor deduction statement, because those are the inputs your refund claim is built from. Get the recording right and the annual work becomes cheaper and more accurate at the same time.
If you want the records and the annual CIS work handled together rather than stitched from two suppliers, our CIS accountancy services page sets out what is covered.