How to write a contractor invoice

A contractor invoice should identify the work, the customer who owes the money, the amount due, the due date and how to pay. Reference the approved estimate and changes, then show tax and payments applied so the balance can be checked.

Requirements depend on the contract and applicable tax, licensing and payment rules. For federal work, read the incorporated prompt-payment clause: FAR 52.232-25 lists invoice requirements, while FAR 52.232-27 addresses construction contracts.

What details should the invoice include?

Names and figures below are invented. Use the shape, not the numbers.

Ask your licensing board which documents must show a license number. For commercial work, keep a completed W-9 ready and use a stable invoice number; invoice numbering and records covers the system.

A finished invoice for a panel upgrade

INVOICE 2026-0184 Ridgeline Electric LLC · License EL-00000 · (555) 010-4180 · [email protected]

Bill to: Hale Property Group LLC, 900 Third Ave, Suite 210 Job: 214 Alder St — 200A service upgrade · PO 4471 Invoice date: August 24, 2026 · Terms: Net 15 · Due: September 8, 2026

Description	Qty	Unit	Rate	Amount
Labor — remove existing panel, install and terminate new service, transfer 22 circuits	12	hr	$95.00	$1,140.00
Materials — 200A load center, breakers, meter socket, conduit, grounding	1	lot	$760.00	$760.00
Electrical permit — city fee, billed at cost	1	ea	$185.00	$185.00

Subtotal: $2,085.00 Sales tax on materials, 6.5%: $49.40 Total: $2,134.40 Deposit paid 8/11, check #1902: −$600.00 Balance due: $1,534.40 by September 8, 2026

ACH: routing 000000000, account 0000000000. Checks payable to Ridgeline Electric LLC. Ask for a card-payment link if you prefer to pay by card.

Three details make the amount easier to check. The descriptions say what was done, not what was "discussed." The deposit is subtracted on the page, so nobody does arithmetic to find the amount owed. And the due date is a calendar date, so the day it goes late is not an opinion.

The tax line charges materials only, at a made-up rate. That is one of several ways states treat work on real property, not a template — see below.

If you want to add a card surcharge, Visa’s rules, other accepted networks and state law set conditions. Confirm them with your processor before offering that option.

Labor and materials on separate lines

Separate lines help explain the bill in three ways.

Tax. Labor and materials can have different tax treatment, and contractors may owe tax as consumers of materials rather than collect it from the customer. California’s contractor tax guide illustrates that distinction. Check your state’s treatment and keep the calculation behind the invoice.

Questions about price. Separate descriptions let you point to the work and materials behind an amount without changing the agreed price.

Claims and pass-throughs. An adjuster may ask for material cost, while permits, dump fees, and inspection fees should say whether they are billed at cost.

Grouping materials as one "lot" line with the contents named, as above, is usually right for residential work — checkable, not a hardware-store receipt. Commercial and insurance work often wants more. What you should not do is use a different level of detail than the document the customer approved; the two get compared.

The sales tax line

Whether you charge sales tax, on what portion, and at what combined rate is state and often local law. If you collect it, show it as a separate line. If a customer claims an exemption, get the supporting document before invoicing. Your state revenue department is the authority; sales tax on materials vs. labor covers what to ask.

Check the commercial customer’s billing requirements

The PO number. Ask whether a purchase order is required. If it is, obtain the number before starting and include it by the invoice number.

The billing contact. Confirm who accepts invoices and which email or portal to use. The person supervising site work may have a different role.

Your W-9 on file, with consistent identification. A business payer uses it to determine the name, taxpayer ID and tax classification for any required reporting. IRS instructions for Form 1099-NEC set thresholds and exceptions, including the general corporate exception and separate payment-card reporting. A DBA may differ from the tax name; show the relationship clearly and send the W-9 securely. Getting paid on commercial jobs covers the rest, including retainage and lien waivers.

Avoid the easy delays

Reference signed change orders, show every payment already applied, send a readable document, and invoice promptly after the work. Which term to use and chasing a late invoice are separate decisions.

The invoice starts on the approved document

The approved estimate provides the customer details, scope, prices and payment terms. The invoice also needs the actual completion or billing date, approved changes and payments received. Keep the records connected so you can explain any difference.

DoneQuote is where the estimate or quote gets built and approved, so those line items and that tax breakout are already written down and already agreed to by the time you bill. Copy the approved details into your invoicing or accounting tool, checking completed work, approved changes and payments received, and when someone questions a line, the approved version and its date sit next to the job.

Keep the invoice traceable to the approved scope, and show separately any authorized changes and payments applied.