What is a change order? A plain-English guide for UK subcontractors
A change order is how extra or out-of-scope work gets recorded, priced and signed off on a UK construction job. Here’s what one needs to include, who signs it and why it protects your money.
By The FieldSnap team
Every change order starts the same way. A site manager walks over with a favour that isn’t in your scope, and somebody has to put a price on it before anyone picks up a tool. A change order is just the document that records that decision. Get it signed before the work starts and the favour stops being a favour. Skip it, and you’ll be arguing about it at the final account in three months.
Change order, variation or instruction: what’s the difference?
On a UK job these three words get used as if they mean the same thing. They don’t quite. An instruction is the GC telling you to do something, on site or in a letter. A variation is the change to the works themselves. And a change order is the paperwork that prices the variation and gets both sides to sign it. If you’re a subcontractor, the change order is the one that matters most, because it’s the piece of paper your payment depends on.
A worked example from site
Say you’re the drylining contractor on a retail fit-out. Mid-morning the GC asks your foreman to board out a plant room that was never on your drawings. The mechanical contractor is behind, and the GC wants to keep the programme moving. It sounds small. Then your foreman counts it up. A day of labour, a delivery, and the crew standing around waiting for the boards to land. None of it is in your scope, and none of it is in your price.
That request is an instruction. The extra boarding is the variation. And the change order is the signed note that says the plant room is additional work, priced and agreed before your crew starts. Without it you’ve handed over a day of free work to a GC who will have forgotten the conversation by Friday.
What a change order needs to include
You don’t need a legal document. You need something clear enough that someone could pick it up in six months and know exactly what was agreed. In practice that’s five things:
- The job and the location. Project, block, level and drawing number, so there’s no confusion about where the work is.
- The scope. One or two lines saying what you’re doing and why it falls outside the contract.
- The price, or the basis of pricing. A lump sum, daywork rates or a schedule of rates, agreed before you start.
- Who asked for it and when. The site manager’s name and the date the instruction was given.
- Signatures. The GC’s authorised person and your own office, with the date.
Take a photo of the work as well if you can. Photographs are the cheapest evidence you’ll ever buy, and they settle more arguments than any clause.
When to push for one, and when not to make a scene
Any time the GC asks for work that isn’t in your scope, you want a change order. That doesn’t mean you stop the job and wave paperwork at people. Most extras get agreed in about two minutes if you’ve got the price ready and a signature pad to hand. The trouble starts when you do the work first and chase the paperwork afterwards. By then the value’s on site and the GC has no reason to hurry.
There will be jobs where you let small bits slide to keep a relationship sweet. Fair enough. Just make it a decision you’ve made on purpose, not an accident you discover at the final account.
What happens if you skip it
Skip the change order and you’re relying on memory. Yours, your foreman’s, and the site manager’s. By the time the final account is negotiated, the GC’s commercial team is looking at a claim with no signature, no date and no photos, and they’ll push back. It’s not malice. It’s how their job works. Unpriced and unsigned extras don’t usually survive to the final account.
Frequently asked questions
Is a change order a separate contract?＋
Not really. It’s a written variation to your subcontract, agreed and signed by both sides. The rest of your contract keeps applying. Think of it as an amendment rather than a new deal.
Who has to sign a change order for it to count?＋
Someone with authority on the GC’s side, usually the site manager or contracts manager, plus your own office. A signature from someone who can’t commit the GC is worth little, so if you’re unsure, ask who’s authorised to approve extras.
Does a change order have to be in writing?＋
In practice, yes. A verbal instruction can be a valid variation under the Housing Grants, Construction and Regeneration Act 1996, but proving the price afterwards is where subcontractors lose. A written change order, even a quick email with a photo, turns “he said, she said” into something you can bill.
What is the difference between an instruction and a change order?＋
An instruction is the GC asking you to do something. A change order is the document that records that instruction, prices it and gets it signed. You can ignore a favour that nobody wrote down. You can’t ignore a signed change order.
Change orders don’t have to mean a fight. Catch the request while everyone is still on site, price it fast and get it signed before the crew moves on. Do that and the favour stops being free.