Every month you send an application for payment. A while later a certificate comes back. Later still, money lands in the account. Three figures, and the distance between them is where a subcontractor’s margin quietly leaks away.
Most commercial teams can say the first number without looking. Ask what was certified against last month’s application on your biggest live job, and how that sits against what you actually applied for, and the room goes quiet. Not because anyone’s careless. The number lives in a certificate PDF, an email thread, and someone’s memory, and nobody’s sat down to line the three up.
Two gaps matter.
The first is applied against certified: you claimed one figure, the certificate came back lower. Sometimes that’s fair. Sometimes it’s a variation that wasn’t recognised, or a valuation that measured to last month. Track it month on month and you catch it while the job’s live. Don’t, and you meet it at the final account, when the argument is hardest and everyone’s memory is thinnest.
The second is certified against paid: the certificate says one thing, the payment says another, or turns up late enough that the certificate stops meaning much. The Construction Act put rules around this in the UK, and late payment still hasn’t gone anywhere. A Construction News survey in December 2023 found three in five subcontractors were underpaid even on jobs that went well.
The first gap is the one worth watching harder, and the reason is that it compounds. An under-certification in month two, left uncorrected, becomes the baseline for month three. By month eight the shortfall is baked in and nobody remembers why. The fix isn’t clever. It’s boring, which is exactly why it doesn’t happen: write down what you applied for, write down what was certified, sit them next to each other, and chase the difference while the job’s still running and people still remember the instruction that caused it.
A spreadsheet holds those columns fine. What it won’t do is stay filled in past month three, tie each variance back to the clause and the instruction behind it, or tell you which of your twelve live jobs has the widest gap this month. That last part lives nowhere, for most firms.
Some of it you can see coming, too. Build UK publishes payment performance data on the larger contractors under the reporting rules; it’s public. If you already know a customer certifies slowly or pays at sixty days, that belongs in how you price the work and how hard you keep the paperwork current, not in a nasty surprise at week forty.
None of this is about what the contract says you can claim. That’s your QS’s call, against the terms. This is about visibility: the three numbers side by side, every month, per job, so the conversation happens in month two instead of at the final account.
If you run a specialist subcontracting business and you’ve never had those three columns lined up across your live jobs at once, that’s the thing worth sorting first.