Question 1

What is the most important thing on an invoice?

Accepted Answer

Clear identification of both parties, a unique invoice number, and unambiguous payment terms. Without these, disputes and payment delays are common.

Question 2

How soon should I send an invoice?

Accepted Answer

Send invoices immediately after delivering work or goods. For ongoing projects, invoice at agreed milestones or at regular intervals (weekly or monthly).

Question 3

What if I make a mistake on an invoice?

Accepted Answer

Issue a credit note to cancel the incorrect invoice, then create a new invoice with the correct details. Never alter or delete a sent invoice — this causes accounting problems.

Question 4

Should I use invoice software or a template?

Accepted Answer

Templates work well for occasional invoicing. If you invoice regularly, use a tool like Invoice.website that tracks payments, calculates taxes, and stores your history.

How to Write an Invoice: Complete Guide