The seven legally required fields
In nearly every European jurisdiction, an invoice is only valid if it carries: a unique sequential number, the issue date, your full legal name and tax identifier, the client's name and tax identifier, a clear description of services, the amount excluding tax, and the applicable tax rate and total. Missing any one of these can disqualify the invoice in an audit and entitle the client to delay payment.
Three fields that are not required but speed up payment
A short reference line like "Project X — March milestone" helps your client's accounts payable team route the invoice without asking you. The exact payment due date as a specific calendar date — never "Net 30" alone — removes ambiguity. One-click payment instructions with IBAN, BIC and a payment link cut the friction to zero.
The polite-but-firm payment terms script
Standard freelance terms are now 14 to 30 days. Anything longer is a financing favor you are giving the client for free. Add a clear late-fee clause: most countries allow 5% above the central bank rate plus a fixed administrative fee. Mentioning the clause does not annoy serious clients — it deters the others.
The follow-up rhythm that works
Three days before due date: a friendly reminder. The day after due date: a neutral notice. Seven days late: a formal notice referencing the late-fee clause. Twenty-one days late: a registered letter. Stick to the schedule and 90% of late invoices are paid by step three.
Generating invoices without spreadsheets
An invoicing tool that auto-numbers, stores client tax IDs, applies the correct VAT rate and produces a clean PDF in two clicks pays for itself the first time you avoid a numbering error. SnapCost includes invoicing on every plan and links each invoice to the related expense report — your accountant will thank you.
The shortest path to faster payment is a clean invoice sent within 24 hours of delivery, with a specific due date and a one-click payment link.