What happened

Build UK published its first retentions benchmark on 12 August, the first time its payment performance table has carried retention data alongside the usual payment-period figures. The organisation, which represents 41 of the UK's largest contractors and specialist trade bodies, collated the numbers after new government reporting requirements introduced in 2025 forced firms to disclose whether they use retention clauses, what percentage they withhold from suppliers, and how much of the retention taken from them by clients gets passed further down the chain.

The headline figures: Build UK's tier one members withhold an average of 2% in retentions. Of the retention withheld from them by their own clients, they pass on 74% to their supply chain and absorb the remaining 26% themselves.

Why it matters

Retentions have been a live grievance in construction for years, not because the percentages are large in isolation but because of what happens when a firm upstream collapses while holding retention money that was never ring-fenced. This is the first time the industry has had an actual benchmark rather than anecdote to argue from, and it lands just as the Department for Business and Trade has confirmed it will legislate to ban retention withholding outright, pairing that with a mandatory 60-day payment cap for large firms paying smaller suppliers. That combination, a retentions ban plus tighter payment terms, is being described as the biggest change to construction payment law in over 25 years.

For contractors, the benchmark is also a reputational marker. Once retention practice is published and comparable, tier one firms that pass on more than their peers, or sit on retention longest, are exposed in a way they weren't before.

What it means for your career

If you're a QS or commercial manager, this is your subject matter, and it's about to get more visible inside your own firm. Boards that have treated retentions as a line item will now face benchmarking against named peers, and someone needs to own the response: tightening subcontract terms, building retention tracking into commercial reporting, and preparing for a post-ban payment model. That's a live skill gap. Commercial and payment specialists who can speak fluently about retentions policy, cashflow forecasting under a 60-day cap, and supply chain risk are going to be in demand at main contractor and tier two level over the next 12 to 18 months, particularly as firms start restructuring subcontract terms ahead of legislation rather than after it.

If you sit in a specialist subcontractor or smaller supply chain business, this is worth raising directly with clients now: asking where you sit against the 74% average is a legitimate commercial conversation, and how a main contractor answers it tells you something about who's worth working for. For anyone weighing a move between contractors, retentions and payment practice are now a due diligence question you can actually put numbers against, not just reputation.