The essentials
Most useful invoices have a supplier identity, customer identity, unique document reference, date, description of services, item quantities and prices, total, currency and payment instructions. Include a due date if you expect payment on a particular date.
If you charge VAT, GST or sales tax, labeling and breakdown requirements may vary. Decide whether prices include tax and present the treatment consistently; never assume the reader can infer it.
Extras that prevent confusion
A purchase order number connects the invoice to a customer approval. Contract or project references help larger customers reconcile payments. Notes can mention a milestone, deposit received or agreed scope; use these only when relevant.
Keep receipts and invoices distinct: the former records payment received; the latter normally requests payment. Your own records should distinguish deposits, part-payments and a remaining balance.
Quality control before sending
Check spelling of client details, arithmetic, bank destination, date order, the currency and any promised payment window. Preview your invoice as a PDF and confirm long descriptions are not clipped. Keep a copy and a reliable backup.
FreelanceKit works offline in the browser after loading, but browser storage is not a cloud backup. Export your data regularly if invoices are important to your business.