The site manager stops you on a Tuesday. The client wants the plant room walls taken up another course, can your lads do it this week? You can, so you do. Six weeks later the application comes back with that line struck through and two words against it: not instructed. You did the work. You were asked to do the work. And on the paper that matters, none of that happened.
This is the most common way a sub-contractor loses money on a job, and it is not a dispute about whether the work was done or whether it was worth something. Everybody agrees it was. It is a dispute about whether the contract recognises it at all, and the contract is not sentimental. A variation is a thing the contract defines, created by a process the contract sets out. Being asked nicely by somebody on site is not that process.
A request is not an instruction
Start with the distinction that everything else depends on. An instruction is a contractual act. It is issued by the person the contract names, in the form the contract requires, and it carries the consequences the contract attaches to it: an obligation on you to comply, and an entitlement for you to be paid for complying. A request is a conversation. It may be perfectly genuine, it may come from someone senior, and it may be exactly what the client wants. None of that converts it into an instruction.
The gap between the two is where "not instructed" lives. The payer is not usually saying the work was not wanted. It is saying that the thing which would have made the work a variation never happened, and that it is therefore under no obligation to pay for it under the contract. On a well-drafted sub-contract, that is a strong position. Arguments about fairness, about who said what in the cabin, about the client having plainly wanted it, run into the same wall every time: the contract allocated the authority to instruct, and that authority was not exercised.
Who can instruct you, and how
So read the clause. Every form tells you who may issue instructions and what form they must take. Under a main contract it is typically the contract administrator or employer's agent. Under a sub-contract it is the contractor, not the employer, not the architect, and not the project manager who happens to be the loudest voice on site. If the person asking is not the person the contract names, you have not been instructed, however reasonable the request.
Then there is form. Most contracts require instructions in writing and give an oral instruction no immediate effect. That is not bureaucracy. It is the only way anyone, months later, can tell what was actually ordered. A reasonable site manager wants you to crack on. A reasonable commercial manager wants a record that you were told to. Both can be satisfied, but only if someone writes it down.
A request is a conversation. An instruction is a contractual act. Only one of them gets you paid.
The verbal instruction and the confirmation window
Most standard forms know perfectly well that instructions get given verbally on site, so they provide a route for it. The pattern is broadly the same across the forms: the oral instruction has no effect on its own, you confirm it in writing within a window the contract sets, and if the other side does not dissent within a further window, the confirmation takes effect as the instruction. The windows are short, usually a matter of days, and the detail varies between forms and between editions, so read your own contract rather than relying on what the last job allowed.
Used properly, that mechanism is the sub-contractor's friend. It means you do not have to down tools and demand paperwork before touching anything. You can do the work and protect the position at the same time, provided the confirmation goes in, on time, in the form the contract requires. Missed, it becomes the problem. A confirmation sent three weeks late, by email to someone who is not the named recipient, is not a confirmation under the contract. It is a letter, and the payer can ignore it.
Doing the work is not the same as being paid for it
Here is the hard truth. If you do work that was never instructed under the contract, you will usually find that the contractual route to payment is closed, and that what is left is an argument outside the contract that is slower, weaker and more expensive than the one you gave up. The position is not hopeless, but it is not where you want to be.
Which leaves a choice, and it has to be made at the time, not afterwards. Either confirm the instruction properly and proceed, or decline, politely and in writing, until it is instructed by the right person in the right way. What you cannot sensibly do is the third thing, which is do the work on trust and hope the account sorts itself out. We have written before about why the final account sorts out nothing. This is the most expensive example of that rule.
How it gets valued
Assume you have cleared the first hurdle and the variation is a variation. The next argument is about money, and it is worth knowing that the contract usually decides this too. The valuation rules in most forms run in an order of priority. Work of similar character to something in the contract, carried out in similar conditions, is valued at the contract rates. Where the character is similar but the conditions or quantities are not, the rates are adjusted. Where there is nothing comparable, a fair valuation applies. Dayworks sit at the bottom, for work that cannot properly be valued by measurement.
That ordering matters, because the instinct on site is to go straight to dayworks for anything unusual. A signed dayworks sheet is a record of the labour, plant and materials used. It is not, on most forms, an agreement to pay for them on a daywork basis, and a payer who can show the work was measurable will value it by measurement, at rates you may find less generous. So get the sheets signed, every day, because the record is valuable. Just do not confuse the record with the valuation.
Some forms also provide a quotation route, where the instructing party asks for a price before confirming the instruction. Where it is available it is usually worth using, because an agreed price before the work is a better position than an argued one after it.
The omission that walks out the door
Variations cut both ways. Work can be omitted as well as added, and omissions are where a different kind of loss happens. A package is reduced, the margin that was priced across the whole job is left stranded on what remains, and the omitted work turns up a month later being done by somebody else.
Be careful here, because the general position is narrower than people assume. A power to omit work is, broadly, a power to decide that the work is no longer required. It is not generally a power to take the work from you and hand it to another contractor, and a payer who does that without a clear contractual right to do so is exposed. The drafting matters enormously and some bespoke forms do try to reserve that right expressly, so this is a clause to read before you sign and to raise, in writing, the moment an omission looks like a transfer rather than a deletion.
A signed dayworks sheet is a record of what you used. It is not an agreement to pay for it.
What good looks like
The businesses that get paid for their variations run a short list of disciplines, every week, on every job:
- They know, from the contract, who can instruct them and in what form, and they brief the site team on it before the job starts.
- They confirm every verbal instruction in writing, inside the window, to the named person, in the form the contract requires. Not a text message to a mate.
- They keep a variation register with a status on every item: requested, instructed, confirmed, valued, agreed, disputed. Anything sitting at "requested" for more than a few days is chased or declined.
- They get dayworks sheets signed on the day and treat them as evidence of resources, not as a valuation.
- They ask for the quotation route where the form provides one, so the price is agreed before the risk is taken.
- They challenge any omission that looks like a transfer, in writing, when it is first instructed.
None of this slows a job down. It takes a few minutes a day from someone who has been told it matters. It is the absence of those few minutes that costs the money, usually months later, in a meeting nobody enjoys.
The work you were told to do
Nobody is suggesting you stop being helpful on site. The job runs on people saying yes. The point is narrower than that: say yes, and then make the contract say it too, in writing, within the window, to the right person. Done that way, the instruction exists, the valuation rules apply, and the line in your application stands.
Done the other way, the work still gets done, the client still gets what it wanted, and you still get two words against the line. Not instructed. It is not that nobody asked you. It is that, on the page that matters, nobody told you.
This is one of the things Defender Platform is built to catch. It records each instruction against the clause that authorises it, flags the confirmation window before it closes, and keeps the variation register current with a status on every line, so "not instructed" is an argument you never have to have.