Most construction projects use progress billing rather than a single invoice at the end. You break the total contract into phases or line items using a schedule of values, then invoice as work gets completed. This keeps cash flowing into your business while the project is still going instead of waiting months to get paid.

Start with a schedule of values before work begins. This is a list of every major phase or cost category on the project with a dollar amount assigned to each. Demolition, framing, rough electrical, plumbing, drywall, finish work. Each gets its own line with a value that adds up to the total contract amount. When you invoice, you bill the percentage of each line item that’s been completed since the last billing cycle.

Your invoice should include the job name and address, the billing period, the original contract amount, any approved change orders, the amount previously billed, the current amount due, and the remaining balance. If the project requires retainage, show that as a separate line. Retainage is typically 5% to 10% held back by the property owner or general contractor until the project reaches substantial completion. You need to track it because that money is owed to you but won’t show up in your bank account until later.

Change orders need to be documented and added to the contract total before you bill for them. Don’t just lump extra work into an existing line item. Keep change orders separate so both sides can see exactly what changed and why the total went up. This avoids disputes when the final invoice arrives.

For time and materials jobs, your invoice looks different. You list actual hours worked by each crew member or trade at the agreed rate, plus materials with receipts or markup. T&M invoicing requires detailed records because the client is paying based on what you actually spent rather than a fixed price.

Set a regular billing cycle and stick to it. Most contractors bill monthly, but some projects use milestone billing where you invoice after completing specific phases. Whatever you choose, invoice promptly. Waiting weeks after work is done to send an invoice signals to the client that getting paid isn’t urgent to you, and they’ll treat it accordingly.

Track all of this in your accounting software tied to the specific job. When invoices, payments, and retainage are recorded at the job level you can see exactly where each project stands financially. If you need help with invoicing and payment tracking, getting that set up correctly from the start saves you from chasing down discrepancies later.

The biggest mistake contractors make with invoicing is being too casual about it. A handwritten invoice with no job detail, no reference to the contract, and no breakdown of completed work gives clients reasons to delay payment or dispute the amount. Professional invoicing backed by clean books protects your cash flow and makes you look like the serious operation you are. If your books are a mess and invoicing feels like guesswork, bookkeeping and tax services for contractors can get your systems organized so billing runs smoothly on every project.