On NEC4 options C, D and E, the single biggest cause of disallowed cost isn't bad faith or bad work. It's bad records. Gather is the AI-powered site diary that captures the evidence to justify every penny of defined cost — automatically.
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Clause 11.2(26) of NEC4 defines six categories of disallowed cost. When a project manager challenges your defined cost, they're picking one of these. Five of the six are evidence problems. If you can prove what happened, when it happened, and why, you keep the money. If you can't, you don't.
Time, equipment hours, people allocation, plant utilisation. If you can't produce a clean audit trail, the cost is at risk.
Overpayment against the subcontract terms, or paying outside the agreement entirely.
No early warning given when one was required. The hypothetical "what would you have done" argument is hard to win on the back foot.
Defects pre-completion are allowable. Defects after completion are not. Which means completion has to be defined clearly in the scope.
Eight pallets of bricks ordered, one used. No narrative on why the excavator stood idle for three days. The money walks.
Disputes the client didn't see coming, or wasn't notified about. Notify late and the costs come out of your margin.
The most common reason for costs being disallowed is the submission of insufficient records to demonstrate the defined cost expenditure.Ben Walker, Gather · NEC4 Webinar Episode 9: Disallowed Cost Explained
We built Gather around the way commercial teams actually work on cost-reimbursable contracts. The schedule of cost components, the early warning register, the defects log, the subcontractor records — all live in one place, captured at the source, mapped to the contract, and audit-ready by default.
Your site team captures time, equipment hours, plant, materials and subcontract activity through a phone-first site diary that takes seconds, not minutes. Every entry is time-stamped, geolocated, and tied to the schedule of cost components.
Every subcontractor payment is built up against the subcontract you've signed. No silent overpayments. No bonus payments outside the agreement. Clause 26.4 submissions become routine instead of confrontational.
The most expensive early warning is the one you didn't send. Gather prompts your team in the field the moment a trigger condition appears — utility strike, weather, design change, programme slip. The procedural risk leaves your balance sheet.
Gather's defect register links every snag to its raise date and resolution date. When a completion certificate is issued, there's no ambiguity about which side of the line each item sits on.
Reasonable wastage is subjective until you've shown the working. Allocation sheets, downtime narratives, stand-by reasons and reuse data — captured live, ready to defend.
Gather's communications log records every notification, every response, and every reminder, so the procedural side never trips you up on the day you need it.
Ben Walker, who appears on the webinar, helped draft NEC4 and founded CEMAR.
Paul Clegg has 20 years building SaaS for construction.
Will Doyle, Gather's founder, nearly lost £20m on the North West Electrification Programme because the records existed but couldn't be found in time.
That's why Gather exists. Not because spreadsheets are bad. Because scattered records cost money.
The webinar walked through what disallowed cost is and where it sits in the payment assessment. In 60 minutes it couldn't show you the operational answer. That's what a Gather walkthrough is for.
In 30 minutes, we'll:
Yes. Gather is purpose-built as the commercial site diary for NEC4 contracts. Your existing diary, daily reports, allocation sheets, photo logs and early warning register all consolidate into one system. Most teams retire 3-5 separate tools when they move to Gather.
That's the point. On options C, D and E, agreement is easier when both sides see the same data. You control what's shared and when, but the audit trail is the same audit trail.
No. We work with consultancies, subcontractors and SME contractors on everything from £2m schemes to £500m+ frameworks. The clause works the same way at every scale.
Two weeks for a typical first project. The pilot starts with one team on one project, then scales across the business.
Gather is ISO 27001 certified. Your data is yours — exportable at any time, and we sign data processing agreements as standard.
Project management platforms manage delivery. Gather manages the commercial evidence layer underneath. Most of our customers run Gather alongside their existing PM tool — it's where the records live, not where the schedule lives.
The cheapest insurance against disallowed cost is a record that holds up the first time someone asks for it. Book a 30-minute walkthrough — bring a real payment assessment you've been chewing on, and we'll show you what the evidence layer looks like underneath it.
Book a 30-minute walkthrough30 minutes. No commitment. No hard sell. We'll send a calendar invite within 4 working hours.