What to include in an engineer invoice
- Project and permit reference. Project name, site address and any permit or plan review number, so the client's accounts team can match the invoice to the job.
- Phase or deliverable billed. Survey, calculations, drawings or certification named on the line with the revision issued, so every fee ties to something delivered.
- Professional hours by role. Hours for principal, engineer and drafter at their own rates, kept apart from subconsultant work such as geotechnical testing.
- Site visits. Each visit dated and listed on its own, since the second and third inspections are the ones that go unbilled when they are lumped together.
- Reimbursable expenses. Mileage, printing, courier and permit fees you paid on the client's behalf, at cost or with your stated markup, backed by receipts.
- Additional services. Work outside the original proposal, such as redesign after a client change, referenced to the written authorization that approved it.
- Fee billed to date. The contract fee, the amount billed so far and the balance left, so a phased job shows where it stands on every invoice.
- PE license and client PO. Your professional engineer license number and state, the firm registration where required, and the purchase order number the client issued.







