1. Gather the details before you start
Write down your business name and contact details, the customer's billing details, the project or purchase reference, and the period covered. If the work happened at a different site, include that address. Starting with these facts prevents a polished-looking invoice from being impossible to match to the job.
- Seller name, address, and contact method
- Customer name and billing address
- Project, purchase order, or site reference
- Billing period or completion date
2. Add identifiers, dates, and line items
Use a number that identifies this invoice in your records. Add the issue date and the due date or payment rule agreed with the customer. Then describe each service or item with a quantity, unit, rate, and line total when those details matter.
Keep labor, materials, equipment, milestones, and approved changes distinguishable when the job requires that detail. A line such as “Replace failed circulation pump, 1 unit” is easier to check than “Repair.”
3. Show the calculation and payment terms
List the subtotal, any tax line that actually applies, credits or previous amounts, and the amount due. State accepted payment methods and the agreed terms. Do not invent a tax rate or imply that a template makes an invoice compliant everywhere.
Compare names, dates, quantities, rates, and the total with your source records before sending. Keep a copy and attach supporting documents when the agreement calls for them.
4. Worked example and next step
“Replace circulation pump — 1 x $480” and “Labor — 4 hours x $95” produce an illustrative $860 subtotal before any applicable tax. The numbers teach the arithmetic; they are not a recommended price or a tax determination.
Start with an Invosmith template when you want a prepared layout, or enter the same fields in the invoice generator when you want to build a document from scratch.
| Line | Quantity | Rate | Example total |
|---|---|---|---|
| Circulation pump | 1 | $480 | $480 |
| Labor | 4 hours | $95 | $380 |
| Illustrative subtotal | $860 |