Note
Your Stage Billing Setup in Week One
The first week of a new project is the last quiet window. The main contractor’s site team is not yet chasing problems. Your own people are not yet deep in the installation. Nobody has missed a deadline. That window closes fast, and several billing decisions that are easy to make in week one become disputes if they are left until month three.
This piece covers the four things to set up in that window, in order, before any work gets billed.
Who signs acceptance, and when must the invoice land?
Two pieces of information are easy to get in week one and difficult to reconstruct later: the name of the person whose signature the main contractor’s accounts team will accept on an acceptance form, and the cut-off date by which invoices must arrive to enter the current payment run.
The signatory matters because main contractor site teams are not organised the same way as payment teams. The site engineer who directs your work on site may not be the person whose signature releases a payment. A signed acceptance form from the wrong person creates a query that holds the invoice while the right person is tracked down. Get the name in writing in week one. A LINE message asking “which of your team should sign our acceptance forms?” is enough. Screenshot it and file it.
The cut-off date is the hard boundary that determines whether an invoice enters this month’s payment run or next month’s. Most main contractors in Thailand process invoices received by approximately the 15th to the 25th of the month. An invoice arriving two days after the cut-off waits a full month, regardless of how complete the package is. If the cut-off date is on the timeline from day one, billing pins can be placed to allow at least ten days between expected acceptance and cut-off. That buffer absorbs the time between site sign-off and invoice preparation.
How do you map contract stages to physical work zones?
A contract stage is described in BOQ language: scope, section, or item number. Physical site work runs in zones, floors, or grid areas that may not align to the BOQ exactly. The gap between those two descriptions is the most common source of invoice queries.
In week one, take the site plan and the contract BOQ and match them. Which zones together constitute stage two? Which BOQ line items are captured in stage four? A one-page table that maps each contract stage to its zones and the corresponding BOQ line references is enough. That table becomes the reference when each invoice description is written. Carrying the BOQ wording through every invoice from stage one onwards means the accounts team can match the invoice to the contract without a follow-up call.
Should acceptance criteria be agreed in writing before work starts?
Acceptance criteria are what the site team inspects before signing the acceptance form. If they are not agreed in advance, the inspector defines them on the day, which turns a routine sign-off into a negotiation.
For most installation subcontracts, the criteria for a stage are straightforward. For a partition and ceiling trade, stage two might be: all tracks and studs installed in zones A and B, drywall on one face, first-fix MEP inspected and signed off, ready for boarding. That description in a message to the main contractor’s site engineer in week one, confirmed by a reply, is a record that both sides agreed to the same standard before any stage was reached.
A confirmed reply is not a legal instrument, but it is far stronger than no record at all when a dispute arrives on stage four.
A worked example: the cut-off date that nobody looked up
A glass and aluminium subcontractor signed a five-stage fit-out contract. Nobody confirmed the main contractor’s payment cut-off date in week one. Stage one was accepted on the 18th and invoiced the same day. The cut-off was the 20th. The invoice made it into that month’s run with two days to spare.
Stage two was accepted on the 24th and invoiced the same day. The cut-off was the 20th. That invoice waited until the following month’s run: one full month of credit period added to a single billing stage.
Had the cut-off date been established in week one, the stage two billing pin on the timeline would have been placed on the 17th, not the 24th. That is a seven-day shift on a single bar, achieved by one question asked in the first week. The work did not run late. The billing setup did.
Setting up the acceptance form pipeline
The acceptance form converts a physical completion into a billing trigger. Before work starts, set up the filing structure.
A folder, physical or digital, for each project. Inside it, one subfolder per stage. An acceptance form received goes into the correct subfolder on the same day it arrives. A form that is not filed on the day it is received is a form that disappears at the worst moment.
Confirm the format the main contractor uses before stage one is submitted. Some use a printed form with a reference number. Some accept a typed confirmation on letterhead. Some will sign your own form. Knowing the format before the first invoice is waiting removes a back-and-forth that delays an otherwise complete package.
FAQ
What if the main contractor will not confirm the acceptance signatory?
Ask the site manager and commercial manager in the same message and note both names. When the first form is submitted, copy both. Whoever responds establishes the precedent for this project. File that response as the authorised signatory record. You are not demanding a formal answer; you are creating a paper trail that protects both sides if a dispute arrives later.
How far ahead should billing pins be placed on the timeline?
Place each pin from day one, based on the estimated acceptance date. Estimate that date from the bar showing the work. If the bar ends on the 12th and the cut-off is the 20th, the pin goes at the 12th with eight days of buffer. Adjust the pin as the bar moves. A pin that was never placed cannot be adjusted; a pin placed from the start moves with the work.
What if the BOQ breakdown does not match the physical work zones?
Map the gap in writing and confirm the mapping with the main contractor’s commercial manager before stage one. You are establishing a shared reading of how the BOQ translates to inspectable work on site, not asking for a contract change. Without that mapping, the invoice description will not match the BOQ on every stage, and each mismatch becomes a query the accounts team has to resolve before payment moves.
If you want to run through this setup on a live project before the first stage is billed, a 45-minute call is the right starting point. We open one current project together and put a date next to each step.