You win the package. You put your people on site. You fund the first month of labour and materials out of your own pocket — and then the certified invoice sits unpaid at 30 days, then 60, then 90. By the time you realise the main contractor was never good for the money, you're the one carrying the debt. Checking a main contractor before you accept the work takes minutes. Not checking can cost you a year's profit.
Why the main contractor is the biggest risk in the chain
As a subcontractor, you are an unsecured lender whether you like it or not. You fund the work up front and wait for the money to flow back down the chain. If the main contractor is slow, unfair or quietly insolvent, it lands on you first and hardest — because you sit furthest from the client's money. That is exactly why a main contractor needs checking harder than anyone else on the job.
1. Will they actually pay? Read the record, not the promises
Every main contractor will tell you they pay on time. The ones who don't tell you the same thing. Ignore the sales pitch and look at behaviour:
- Do certified invoices get paid on time — or does 30 days quietly become 90? Late payment is the single clearest predictor of a bad relationship.
- Do they raise deductions and back-charges that were never agreed? A contractor who invents reasons not to pay will find one for you too.
- Do they return retention when it falls due? Held retention that never comes back is one of the most common ways subcontractors lose money — legally owed, quietly withheld.
- Do variations get confirmed in writing before the work is done? “Just crack on, we'll sort it later” is how five-figure claims turn into unpaid disputes.
This is exactly what CIX measures. Every certified invoice is a legally owed payment, so we pool them into a single payment score built from real dates — not opinions — plus hard flags like abandoned invoices. One search shows you what would otherwise take twenty phone calls to other subcontractors.
2. Check the company and the people behind it
A main contractor is only as safe as the company holding your money and the directors running it:
- Company status, age, filings and charges — the free Companies House checks that flag distress. Overdue accounts and a stack of recent charges rarely appear on a healthy business. Our guide to checking a construction company walks through each one.
- The directors' other companies. A director with four dissolved companies behind them is showing you a pattern, not bad luck. CIX draws this as a connection map on every report and screens each current director against the disqualified-directors register automatically.
3. Match the package to the company's size
A main contractor with £200k of net assets handing you a £600k package is a mismatch, whatever the explanation. Check the last filed accounts and ask the honest question: could this company absorb one bad month without taking your money down with it?
4. Watch for the distress signals
A main contractor in trouble behaves in recognisable ways before it collapses. If you spot several of these together, protect yourself now — don't wait for confirmation:
- Suppliers put the account on stop, or you're asked to buy materials “to keep things moving”.
- Certifications and valuations are chased aggressively — the company is pulling cash forward.
- Key people leave suddenly; the QS or contracts manager stops returning calls.
Our warning-signs guide covers the full pattern — and what to do when the flags line up.
Protect yourself before you sign
- Check them on CIX first. A two-minute search tells you how this contractor treats the subcontractors who came before you.
- Negotiate terms that reflect the risk. If the record is thin or poor, ask for shorter payment terms or reduced retention — and price the risk in.
- Get everything in writing. Instructions, variations, agreed rates. If it ends in a dispute, paper is all that counts.
- Then add your own report. It's free, it's moderated, and it protects the next firm in line — which is the whole point of CIX.
The subcontractors who don't get burned aren't luckier — they check first. Search a main contractor now, or add a report on one you've worked with. The more the trade shares, the fewer firms get caught.