How to Invoice as a Contractor
By ActiveEngine · 6 min read · Last updated August 27, 2026
What a contractor invoice must include
Every invoice needs six things: your business name and contact details, the client's name and job address, a unique invoice number, the invoice date, an itemized list of labor and materials, and the total due.
Leaving out the job address is the most common mistake on trade invoices. If a client manages several properties, an invoice without an address sits in a pile until someone works out which job it belongs to.
Numbering invoices so nothing gets lost
Use a simple sequential system — 1001, 1002, 1003 — and never reuse a number. Sequential numbering makes it obvious when an invoice is missing and keeps your bookkeeping clean at tax time.
If you work for several general contractors, prefix the number with a short client code (ACME-1001) so you can find any invoice in seconds.
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Split labor and materials into separate line items with quantity and rate. Clients approve invoices faster when they can see how the total was built rather than a single lump sum.
Round hours to the nearest quarter hour and describe the work in plain language: "Replace 40-gallon water heater, including haul-away" beats "plumbing services."
Payment terms that actually get you paid
Net 15 is the sweet spot for residential work; Net 30 is standard for commercial. State the due date explicitly on the invoice instead of only the terms — "Due September 11, 2026" outperforms "Net 15."
Add a short late-fee line (1.5% per month is typical) and list every payment method you accept. Friction in paying is the number one reason invoices go past due.
Sending and following up
Send the invoice the same day the work is finished — collection rates drop sharply after 48 hours. Attach it as a PDF so it looks the same on every device.
Follow up at day 7 and day 14 with a short, friendly message that restates the invoice number and amount. Most late payments are oversights, not disputes.