Milestone Billing

How to structure milestones

A typical four-milestone structure for a 12-week project: 25% deposit at signing, 25% on completion of discovery/design, 25% on completion of build, 25% on launch. Variants tie milestones to specific deliverables (wireframe approval, beta release, final acceptance) rather than time.

Each milestone should be objectively defined ('signed-off design files delivered' beats 'design phase complete'). Otherwise you'll spend the project arguing about what counts as done.

Why it beats monthly time-and-materials

Monthly T&M billing exposes you to dispute risk: the customer can challenge the hours, request adjustments, and slow the next month's payment. Milestone billing ties payment to a discrete, accepted deliverable.

Cash-flow-wise, milestone billing typically pulls 60-80% of project revenue forward versus billing only at completion. For a service business with 60-day DSO, that's the difference between funding payroll comfortably and chasing it every two weeks.

Designing milestones that protect cash

The most cash-friendly milestone structure is front-loaded: 33% on contract signing, 33% at the mid-project review, 34% at delivery. This keeps you ahead of cost throughout the project and ensures you've already collected most of the contract value before you've delivered the bulk of the work. The customer's incentive to complete the project remains intact because the final payment is tied to acceptance.

Define milestones around objective deliverables rather than calendar dates. 'Payment due upon delivery of the wireframes' is enforceable; 'payment due in 30 days' is not, because the customer can argue the deliverable wasn't ready or wasn't acceptable. Each milestone should have a definition-of-done that both parties signed before work began.

Build in invoice-and-pause clauses for late milestone payments. If milestone 2 isn't paid within 15 days of invoicing, work stops until it is. This sounds confrontational but it's actually protective: a customer who can't or won't pay milestone 2 is unlikely to pay milestone 3, and the further you proceed before stopping, the more cash you're at risk of.

A subtle but important detail: every milestone invoice should reference the contract by number and the milestone by name, with a clear acceptance criterion noted. AP departments at larger companies route milestone invoices through different approval paths than recurring invoices, and missing context is the single most common reason these invoices stall in approval queues for weeks.