What if my variations are only disputed at the final account?

A late dispute changes the tactics, not the entitlement: the instruction and the records still decide whether you get paid. The final account is the overall reckoning of what is owed at the end of the job, and payers often hold variations back to that stage because it is where their leverage is greatest and your evidence has aged the most. The response is to rebuild each disputed variation as its own self-contained file, from the instruction through to the valuation, rather than defending one big lump sum. Check what earlier payment applications and certificates already accepted about each change, because an amount a payer has previously certified is hard to take back. A certificate is the formal document confirming how much is due for a period, so it can lock in ground you have already won. Adjudication, the fast dispute process usually decided within about twenty-eight days that construction contracts must make available, can be run on individual variations without reopening the entire account. The far better answer, though, is not to let it get this far: apply for and settle each change in the month it happens, while the facts and paperwork are fresh.

Say a plumbing subcontractor finishes a care home job carrying twelve variations worth around £90,000 in total. Throughout the job the main contractor paid on account without ever formally agreeing the changes, and now, at the final account, lumps all twelve into a single line and offers a fraction of the total, betting that a year on the subcontractor cannot prove the detail. Rather than argue about one big number, the subcontractor breaks the claim back into twelve separate files, each running from the instruction that triggered it to the records and valuation behind it. Going through old interim certificates, the subcontractor finds four of the variations had already been certified in full months earlier, which the contractor now struggles to walk back. For the rest, the subcontractor can take a single stubborn variation to adjudication on its own, the roughly twenty-eight day process, without reopening the whole account. The entitlement was always there; rebuilding change by change is what makes it provable once the dispute has been left late.