AI for construction companies

AI for construction companies earns its keep in the office, not on site: reading subcontractor applications, drafting payment notices before the statutory deadline, working out CIS deductions, issuing payment and deduction statements and preparing the monthly return. Each of those jobs has a fixed trigger, a legal date and a document at the end. Valuing work, deciding to pay less than was applied for and verifying a new subcontractor whose details don't match stay with a named person.

The sector is large and slow to adopt. The government's 2025 business population estimates count 885,000 construction SMEs, 16% of the UK total and more than any other sector. Yet in the ONS's June 2026 survey only 13% of construction firms reported using AI, while information and communication businesses stood at 58%.

One valuation, three sets of rules

A single monthly payment to a subcontractor passes through the Construction Act, the Construction Industry Scheme and, between VAT-registered firms, the domestic reverse charge. Each sets its own date. The penalties sit in this paperwork, not on site.

The table follows the default statutory scheme. A bespoke subcontract can move the due date and the final date, so the system should read the dates from each contract rather than assume them. The CIS penalties show why a missed 19th matters: £100 for a return one day late, £200 at two months, and at six months £300 or 5% of the CIS deductions on the return, whichever is higher. Records that can't be produced for HMRC can cost up to £3,000.

A worked example: 12 subcontractors

Picture a groundworks or fit-out contractor paying 12 subcontractors every month, each on a monthly application cycle. That's an assumption to show the volume, not a client's books.

• Payment notices: 144 payment notices a year, each on its own 5-day clock.
• CIS statements: 144 payment and deduction statements a year.
• Monthly returns: 12, one per tax month.

That's 300 dated documents a year, before a single pay less notice, verification or reverse charge check. If every return in a year slipped by one day, the first-stage penalties alone would come to £1,200.

The work behind those documents is reading, matching and calculating. An application arrives as a PDF or spreadsheet, gets compared line by line with the previous valuation, and its figures flow into the deduction and the statement. Our guide to intelligent document processing shows how to test extraction on your own applications first. Where materials arrive with delivery notes, the checks in three-way matching apply too.

The reverse charge check on every invoice

HMRC's domestic reverse charge covers standard and reduced rate building services between VAT-registered businesses where the payment is reported under CIS. The subcontractor doesn't charge VAT on the invoice. The contractor accounts for it instead. A homeowner commissioning an extension sits outside CIS, so a builder's invoice to them carries VAT as normal.

Errors creep in at the edges. A subcontractor charges VAT out of habit, or a supplier who also fits what it sells treats the job as a plain materials sale. A system reading each incoming invoice can test three things before it reaches the ledger: is the supplier VAT-registered, is the payment going on the CIS return, and does the invoice carry the reverse charge wording. Our accounts payable automation guide covers the rest of the invoice route, and supplier statement reconciliation catches what slips through at month end.

Decisions that stay with a person

Software should prepare these and stop:

1. The valuation. What the work on site is worth is a quantity surveyor's judgement. The system can lay last month's figure next to this month's claim and highlight the lines that moved.
2. A pay less notice. It's a commercial decision with legal consequences, and the reason in it needs to stand up in adjudication.
3. A verification mismatch. HMRC needs the details to match exactly. When they don't, someone has to call the subcontractor rather than let the system guess.
4. Suspension. A subcontractor who isn't paid can suspend work after giving at least 7 days' notice. When one of those notices arrives, it goes straight to a director.

Site safety sits outside this guide's scope, with one exception: a reminder. Under CDM 2015 the client must notify HSE when work is expected to last longer than 30 working days and have more than 20 workers working at the same time, or exceed 500 person days, and a project tracker can flag jobs that cross the line. Each of the four decisions above becomes an approval gate, and the first months run in shadow mode beside the existing process.

Where a contractor should start

Start with payment and deduction statements. They follow mechanically from payments already approved, every subcontractor gets one, and lateness is easy to count. Pull last year's dates from your accounts package and see how many went out after the 14-day limit. Then move up the chain to payment notices, where the deadline is tighter and the sums larger. Before any build, check that subcontractor records hold clean UTRs and company numbers; data readiness for AI describes a 50-record test that answers it in an afternoon. An AI audit ranks the remaining jobs by hours.

Common questions

Two figures from your accounts package will shape the conversation: how many subcontractors you paid last month, and how many payment and deduction statements left after the 14-day limit over the past year. Send them through the contact form under Business automation, with the name of the software you run CIS in. After a short, informal scoping chat about how your CIS month runs, we'll come back with a price range for the work.