How does milestone billing work?
Payment is tied to defined milestones — design complete, foundations poured, a floor topped out — rather than to elapsed time or delivered goods. The matching document is the certificate, not a receipt: the engineer or project manager certifying that the milestone has actually been achieved. Same triangle as any other payment, with a different document in the middle.
The certificate is the delivery note
A lump-sum or milestone scope has nothing to receive at a gate. There is no truck, no weighbridge, no goods received note. So the middle document of the three-way match becomes the completion or progress certificate.
Commitment, verified performance, invoice. The logic is unchanged — a system that can only match against physical receipts will reject every subcontract invoice you have, and then somebody will start paying them outside the system, which is worse than never having had one.
What makes a milestone billable
It has to be objectively verifiable, and it has to be verifiable by someone other than the person claiming it. “Substantially complete” is not a milestone. “Level 3 slab poured and cured, inspection passed” is.
The vaguer the milestone, the more the certification becomes a negotiation — and a negotiation held every month, with the same counterparty, over the same ambiguity, is a relationship being slowly spent.
And it still bears retention
Certify the gross value of the milestone, deduct retention per the contract, pay the net, and keep the ledger. A matching engine that does not understand retention will flag every deduction as a variance, and within a month your exception queue will be pure noise.
Match gross. Pay net. Track the difference.
Terms
References
- module: /modules/invoices/ — certification as the matching document for services and lump-sum scopes
Zepth is the construction project delivery platform — it runs construction, procurement and asset management on one record, and does the work: reading the drawings, reviewing the submittals, matching the invoices and flagging the risks, with a human sign-off on anything consequential.
Related questions
See Zepth on your project.
A short, tailored walkthrough on your real workflow — no generic demo.
Book a meeting