Free Invoice Template

What makes an invoice complete

An invoice is a demand for payment, and a weak one is the most common cause of slow payment. Most late payments are not refusals; they are invoices that could not be processed because something the payer's accounts system required was missing.

• The word Invoice, so it is not filed as a quote or a receipt
• A unique invoice number, never reused
• Issue date and a specific due date, not just "30 days"
• Your full trading name, address and contact details
• The customer's name and address exactly as they expect it
• A purchase order or reference number if the customer uses them
• Line items with description, quantity and unit price
• Subtotal, tax rate and amount, and the grand total
• Payment instructions: bank details, accepted methods
• Any amount already paid, and the balance now due

Payment terms that get paid

"Net 30" is a convention, not an instruction, and it is interpreted differently by different accounts departments: thirty days from the invoice date, from receipt, or from the end of the month of issue. State an explicit calendar due date alongside the term and the ambiguity disappears.

Shorter terms are paid sooner on average, but only where they are agreed in advance. An invoice that unilaterally demands seven days against an agreed thirty tends to be paid in thirty anyway and damages the relationship in the process.

Invoice numbering

Numbers must be unique and should be sequential. Sequential numbering lets you and any auditor see that no invoice is missing. Many jurisdictions require an unbroken sequence for tax-registered businesses.

A prefix is useful once you have more than one client or year: INV-2026-0043 sorts and files more predictably than 43. Avoid restarting the sequence per customer, which makes gaps invisible.

Following up on a late invoice

Before escalating, confirm the invoice actually arrived at the address that processes payments rather than at your day-to-day contact. A large share of overdue invoices are sitting in an individual's inbox rather than in the accounts system.

Keep the record clean: reissue with the same invoice number and a note rather than creating a second invoice for the same work, which will eventually be paid twice or not at all.