Note
When Scope Changes On Site: Get Confirmation First
The site engineer walks past your crew on day four and asks whether you can add three more light fixtures in the packing room while you are there. Your foreman says yes. The crew takes two hours to run the cable and hang the fixtures. Three weeks later at final handover, the customer’s procurement department processes payment against the original scope only. The packing room fixtures are not in the job order. You have no written confirmation that anyone agreed to them.
This is the scope change problem. It is not about dishonest customers. It is about what happens when a reasonable verbal agreement on site leaves no trace in the paperwork.
What counts as a scope change?
A scope change is any work not described in the original job order or agreed scope document. For a Thai factory electrical contractor, common ones look like:
- Additional fixtures or panels beyond the quoted quantities
- Extra cable routes or conduit not in the original drawing
- Work in areas not originally scoped (“while you are in the ceiling…”)
- Labour-heavy additions to connect equipment that was not on-site when the project was quoted
Minor adjustments within the agreed scope (choosing a different cable route that adds a few metres, shifting a fixture position by one bay) are not scope changes. They are installation decisions. The question is whether the addition requires materials, labour, or time that was not in the original price.
Why does a verbal yes on site fail at handover?
There are three reasons verbal agreements fail:
Authority. The person on site who said yes is often not the person who approves invoices. A site supervisor has operational authority to direct your crew. They do not always have financial authority to commit additional budget. By the time your invoice arrives, the supervisor’s agreement may not bind the finance department.
Memory. Disputes over extras rarely happen on the day the work was done. They surface three to four weeks later when someone in procurement is reconciling the contract against the invoice. Nobody on either side clearly remembers the exact scope of what was requested, or who asked.
Documentation. A signed handover on the original scope does not automatically include extras. If the handover checklist covers only the quoted scope, the extra work is invisible on paper, even if it is physically on the wall. The extra fixtures belong in the record of what was installed and accepted in the same detail as the original scope.
What does a minimum viable field change look like?
You do not need a formal contract amendment for every small change. You need enough of a paper trail to close a dispute if one arises. The minimum:
- A written description of the extra scope (where, what, how many)
- An acknowledgment that additional cost applies, or a confirmed unit quantity
- A reply from someone with authority confirming you can proceed
A LINE message works. An email works. A signature on a printed note works. What does not work is a verbal instruction, even in front of witnesses, because the customer’s recollection will be different by the time anyone checks.
The key discipline: capture this before your crew starts the extra work, not after.
A worked example on real numbers
Project: LED retrofit in a 4,000 sqm warehouse. Original scope: 120 high-bay fixtures in the production hall, quoted and agreed.
On day three, the facility manager asks to add 36 fixtures in the loading bay. The crew is already set up on-site. The manager says it will be a straightforward add-on.
Scenario A: the foreman says yes and tells the crew to proceed. The job order still shows 120 fixtures. At handover four weeks later, the facility manager has transferred to another site. The incoming contact queries the additional line on the invoice. You have no written instruction from the original manager, only a faint recollection of a conversation.
Scenario B: before the crew starts, the foreman sends a LINE message to the facility manager: “Please confirm: add 36 LED fixtures to loading bay, same spec as production hall, price to be added to final invoice.” The manager replies: “Confirmed, go ahead.” The foreman screenshots the reply and attaches it to the job order.
At handover in Scenario B, the 36 fixtures appear in a separate line item with the confirmation attached. There is no dispute.
The 90 seconds to send and receive that message is the entire cost of Scenario B.
What if the site contact refuses to confirm in writing?
Stop the extra work. This is uncomfortable but it is the right move.
A customer who genuinely authorized the work will not object to confirming it in writing. If someone is reluctant to confirm something they have already authorized, that reluctance is information. It usually means the authorization does not actually exist at the level that controls the budget.
“We will sort it out at the end” translates, in practice, to: I cannot authorize this but I want you to do it anyway. That is not a position that protects your invoice.
FAQ
How small does a scope change have to be before I can skip the confirmation?
If the extra work uses materials already on-site and takes under an hour, you might absorb it without a separate trail. Anything requiring materials ordered for the purpose, or more than a few hours of labour, warrants a written confirmation before you start. The threshold is not a fixed number. The test: could this become a disputed line item at invoice time? If yes, document it first.
What if the site contact says they do not have authority to approve?
Wait for someone who does before starting the extra work. This may mean pausing the crew for a day while approval travels through the customer’s chain. The alternative is doing the work on the word of someone who cannot commit the budget, which recreates the original problem. A short pause is always cheaper than an invoice dispute.
Can photos of the completed work substitute for a written change order?
Photos prove the work was done. They do not prove anyone agreed to pay for it. The two records do different jobs. Capture both: written confirmation before starting, photos of the completed work before sign-off.
Closing the loop
The most reliable field change process is one where extra work cannot reach the handover checklist unless a written confirmation is already attached to the job order. That way, the question “was this authorized?” is answered before the handover meeting, not during it. It is the same gate logic one step earlier: the job does not move until the paperwork behind it does.
The TRACE 30 program sets up job orders that carry scope additions with attached confirmations, and a closing gate that flags unresolved items before any job reaches billing. To see how that fits a factory electrical business, read the program details or book a short call.