Note
Variation Work That Never Gets Billed
Variation work is the most expensive item on most construction projects that never appears on an invoice.
The crew gets an instruction: a phone call, a message in the LINE group, a word from the main contractor’s site engineer. They do the work. The next instruction arrives before anyone has priced the first one. Three weeks later, the site manager remembers a changed detail but cannot reconstruct what the original scope said, how long it took, or who authorised it. The work gets absorbed into the project cost and nobody bills for it.
This is not carelessness. It is the predictable result of running sites where instructions move faster than paperwork.
Why extra work disappears before anyone prices it
Work always starts faster than documentation does. A main contractor’s site engineer can give a verbal instruction in thirty seconds and the crew can begin within the hour. Getting that same instruction into a written variation order, priced against the BOQ and signed by someone with authority, takes days or weeks.
By the time anyone circles back to price it, the site has moved on. The crew who did the work is two zones over. The original instruction is a voice note in someone’s phone, buried under forty more messages in the LINE group. Nobody can agree on how long it took or what materials it needed.
Then the billing stage closes. The invoice goes out. The variation never makes it onto the claim. The money was spent, the work was done, and the invoice was zero.
What actually qualifies as variation work?
This is worth stating clearly, because the boundary matters when a main contractor pushes back.
Work qualifies as a variation when it falls outside the original scope defined in the contract and BOQ. Common examples in installation and fit-out work:
- A changed specification, such as a different wall finish or a modified bracket detail
- Work done to fix something that was not your team’s fault, for example a structural surprise once the ceiling was opened
- Scope added after the original contract was signed, such as a second coat of fire-rated paint not in the original drawings
- Work done out of sequence because another trade ran late, which required your team to remobilise to the same zone
Work does not become a variation because it was harder than expected or took longer than estimated. Difficulty is a risk the contractor prices into the original bid. Changed scope is a risk that belongs to the party who changed it. That distinction is what makes a variation claim defensible.
Why does “we will sort it out later” cost so much?
The phrase sounds reasonable at the time. The relationship with the main contractor is what you live on. Stopping work to write up a variation instruction feels bureaucratic when everyone is trying to hit a milestone.
But “sort it out later” has a well-documented outcome: later never arrives with the same information that now has. By the time a variation claim lands on the main contractor’s desk, the site engineer who gave the instruction has moved to another project. The person reviewing the claim has no memory of the conversation. Their first question is always the same: why was this not documented at the time?
A variation that arrives the same week as the work is reviewed differently than one that arrives three months after the fact. The gap is not a rule written anywhere. It is what happens when one side has the paper trail and the other does not.
A capture habit that takes less than three minutes per instruction
The fix is not a new system. It is a decision made before the crew says yes to an instruction.
Before work starts, one person writes down three things:
- What was instructed, in one sentence
- Who gave the instruction and by what method: phone call, LINE, in person
- When the instruction arrived
That note goes into a single running document, one per project, updated every time an instruction arrives that was not in the original scope. Weekly, whoever holds the plan reviews the list and checks each item against the outstanding billing stages.
Items matching an existing stage get attached before the invoice goes out. Items too large or different become a separate variation claim submitted alongside the next payment application.
The capture does not require authority. It requires one person being assigned the habit before the project starts.
Getting a variation accepted: what to hand over
A variation claim that the main contractor accepts on the first submission tends to have three things:
A written instruction from their side, even if it is just a screenshot of a LINE message with a date and a sender’s name. A unit rate from the original BOQ, or a market rate with a source, not a lump sum estimate written after the fact. A quantity verifiable from the site, not a number that came from memory.
These three things do not guarantee acceptance. They do eliminate the most common reasons for rejection. A contractor who wants to dispute a well-documented variation has to dispute the instruction, the rate, or the quantity, all of which have a paper trail. That is a different conversation than the one that starts with “we have no record of this.”
When is it too late to claim a variation?
Most contracts set a notice period, typically 14 to 28 days from the instruction date. After that window, the claim is not automatically void, but the main contractor has grounds to argue that late notice prevented them from checking the work while it was visible. Submitting late is still better than not submitting, but checking the notice clause in a contract is the first step before signing, not after a dispute starts.
What if the main contractor says the work was already included in scope?
This is the most common pushback. The answer depends on the original BOQ. If the item is listed by name with a quantity and unit rate, it was priced. If it is absent, or if the description is narrower than what was actually done, that is the basis for a claim. Asking the main contractor for the specific BOQ line they are relying on usually narrows the argument to something that can be resolved with paperwork rather than memory.
Can variation work be added to an existing billing stage?
Yes, and this is usually the cleanest path when the variation is small relative to the stage value. It avoids creating a separate claim process and keeps the invoice clear for the main contractor’s accounts team. The variation still needs its own line in the invoice with a reference to the original instruction, even when bundled into an existing stage. One line is enough. It is the absence of any reference that triggers the follow-up call that delays payment.
If you are not sure how much variation work is sitting unpriced across your current projects, a 45-minute call is a good place to start. We open one set of project files together and count what is there.