An invoice is a formal request for payment, and the difference between getting paid in three days and chasing a client for three weeks often comes down to how clearly it is written. A good invoice answers every question your client's bookkeeper might ask — before they ask it.
Every invoice should include: your business name and contact details, the client's name and billing address, a unique invoice number, the issue date and a clear due date, an itemized list of what you delivered (with quantities and rates), any tax or discount applied, the total amount due, and how to pay you — bank details, payment link, or accepted methods. Missing any one of these is the most common reason invoices get parked in an accounts-payable queue.
Number invoices sequentially. A simple scheme like INV-001, INV-002 keeps your records audit-ready and makes it easy to reference an invoice in follow-up emails. Never reuse a number, even for a cancelled invoice — issue a credit note instead.
Set explicit payment terms. "Due on receipt" or "Net 14" beats "payment appreciated soon". Studies of freelance invoicing consistently show that shorter, concrete terms get paid faster, and that adding a specific due date (not just "Net 30") reduces late payments. Politely stating a late fee — even a small one — signals that you take terms seriously.
Itemize your work. "Web design — $2,400" invites questions; "Homepage design (2 revisions) — 12 hrs × $200" doesn't. Clients approve invoices they understand.
InvoiceKit handles the formatting for you: fill in the form above, watch the live A4 preview update as you type, and download a print-perfect PDF. Everything runs in your browser — your client data is never uploaded to a server — and your work autosaves locally so a closed tab never costs you an invoice.