The short version
- Tie each invoice to a defined installation milestone.
- Track scheduled invoice dates and expected collection dates separately.
- Record changes and any agreed retainage before forecasting the final receipt.
A commercial film project has more than a customer and a checkout. The building contact approves access, an authorized buyer approves the scope, and accounts payable releases the money. On some jobs, those are separate people with separate deadlines.
Before ordering material, put the installation stages and expected collections on the same page. A deposit helps only after the money arrives. A progress invoice raised on Friday does not fund payroll on Friday if the contract gives the buyer another month to pay.
Use with this guide
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Start with the approved glass schedule
Identify the site, film product, measured coverage, removal work, access arrangements, and installation phases. State who signs off on the scope and who approves an added area. Record exclusions so an unpriced request for another doorway does not disappear into a site conversation.
Express Window Films publishes a proposal form and an example with residential and commercial selections, film details, and deposit fields. Your payment schedule should sit beside that level of scope detail. A single project total leaves the billing team guessing which area was completed when a progress request arrives.
Sources for this section: Express Window Films: installation proposal form · Express Window Films: example installation proposal
Give each payment a verifiable trigger
Use milestones both parties are able to recognize: agreement signed, specified material ordered, first-floor installation accepted, or final punch list closed. The exact schedule belongs in the contract. A percentage without a trigger is difficult to administer when access or material delivery changes.
If retainage is part of the agreement, record the amount withheld and the release condition separately. Do not assume a standard retainage percentage. Some projects have none. Also record submission requirements, such as a buyer PO or acceptance signature, before treating a milestone invoice as ready to collect.
| Stage | Evidence for invoice | Collection question |
|---|---|---|
| Deposit | Signed scope and agreed schedule | Must funds arrive before ordering? |
| Material commitment | Specified order or delivery record | Is this a billable milestone? |
| Installation phase | Completed area and required approval | Who accepts the phase? |
| Final balance | Completion and agreed closeout records | When is payment due? |
| Retainage, if agreed | Contract release condition satisfied | Who authorizes release? |
Worked example: a $12,000 installation
Consider a fictional project with a $3,600 deposit received, $4,800 collected after an installation phase, and $3,600 collected at completion. The shop pays $4,500 for materials before the second payment. Its temporary cash gap is $900.
By the time the second payment arrives, assume another $2,000 of job costs has been paid. Cumulative receipts are $8,400 and cumulative cash costs are $6,500, leaving $1,900 ahead on these listed flows. If a further $1,000 is paid before final collection, the final difference is $4,500. That difference is not net profit: the simplified example excludes overhead, tax, financing, and transaction fees.
| Point in schedule | Receipts to date | Cash costs to date | Receipts less cash costs |
|---|---|---|---|
| Deposit received | $3,600 | $0 | $3,600 |
| Material purchased | $3,600 | $4,500 | −$900 |
| Phase payment collected | $8,400 | $6,500 | $1,900 |
| Final payment collected | $12,000 | $7,500 | $4,500 |
Update the schedule when the building changes the job
Added glass, changed film, delayed access, and extra removal work affect different parts of the schedule. Record the requested change, added price, approval, and effect on collection dates. Update the forecast after agreement instead of leaving the extra amount for a disputed final invoice.
Keep credit notes visible too. If an area is removed from scope, reduce the appropriate balance and reconcile any deposit already applied. Avoid a second spreadsheet whose total no longer matches the current approved proposal.
Print the project collection worksheet
Use one row for each agreed milestone. Put the expected collection date beside the invoice date. The gap between those dates determines how long your business funds the work.
| Milestone / approved amount | Cash costs due first | Invoice / expected collection |
|---|---|---|
| Deposit: __________________ | $_______________ | ________________ |
| Material stage: ___________ | $_______________ | ________________ |
| Installation phase: _______ | $_______________ | ________________ |
| Approved change: __________ | $_______________ | ________________ |
| Final balance: ____________ | $_______________ | ________________ |
| Agreed retainage: _________ | $_______________ | ________________ |
Free to download without an email address. Fill in business or customer details only in your own records.
Confirm the final collection method early
A buyer might expect to use a corporate card after procurement approved a single project total. Discuss payment choices before signing, then keep the agreed pricing consistent in proposals and invoices. Review contract terms and the processor-approved setup before using dual pricing.
At closeout, reconcile the original amount, approved changes, credits, payments, and remaining balance. Send the exact supporting records the buyer requested. The final payment request should explain an existing agreement, not introduce a new price.
Questions business owners ask
Is a 50% deposit standard for commercial window film?
There is no single deposit appropriate for every project. Material terms, access, project size, buyer requirements, and applicable law affect the agreed schedule.
Does a progress invoice mean the money has been collected?
No. Keep invoice, acceptance, due, and received dates separate. Use the received date when reviewing actual cash flow.
Primary sources
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