The hourly-versus-fixed decision shapes your proposal, but it also shapes your invoice — the two look different on paper, and clients read them differently. Here's how each format works as line items, with complete examples you can open in the editor.
How an hourly invoice reads
On an hourly invoice, quantity is hours and rate is your hourly rate. The skill is in the descriptions: group hours into meaningful chunks of work with date ranges, rather than one opaque "21.5 hours" line. Detailed lines answer the client's "what did I pay for?" before it's asked — and they're your protection if a line is ever questioned.
Hourly example: 21.5 hours across three work chunks
Sam bills 14 hours of development, 5.5 hours of fixes and testing, and 2 hours of deployment — each as its own line with dates, all at $85/hour, totaling $1,827.50. The terms note where hours were logged.
Two hourly-invoice habits worth adopting: bill in consistent increments (quarter-hours are standard), and invoice on a fixed rhythm — weekly or twice monthly — so no single invoice grows big enough to scare anyone.
How a fixed-price invoice reads
On a fixed-price invoice, quantity is 1 and rate is the agreed price — per deliverable. Resist the urge to break a fixed price back into hours: it invites hourly-style scrutiny of a price you set on value. Split lines by deliverable instead.
Fixed-price example: the same project, quoted flat
The same feature billed as a $1,800 flat price plus a $250 post-launch support package — two clean lines, with the terms noting the 50% deposit already received on a previous invoice.
Which one should you use?
| Situation | Better fit |
|---|---|
| Scope is fuzzy or likely to change | Hourly — you're paid for reality, not the estimate |
| Scope is crisp and you're efficient at it | Fixed — your speed becomes margin, not a discount |
| Ongoing maintenance or support | Hourly, or a monthly retainer billed as a fixed line |
| First project with a new client | Fixed with a 50% deposit — limits risk on both sides |
Mixing both on one invoice
Completely normal, and often the most honest format: a fixed line for the agreed deliverable, plus hourly lines for out-of-scope requests that came up along the way. Keep the hourly lines clearly labeled ("Additional revisions beyond scope — 3 hrs × $85") so the distinction is visible at a glance — that visibility is also what teaches clients that scope changes have a price.
Both example invoices above open in the free invoice generator — swap in your details and download the PDF. And whichever format you choose, the payment terms you write matter just as much as the numbers.