Invoice

An invoice is a commercial document issued by a seller to a buyer that itemizes the products or services provided, their quantities, prices, and the total amount owed. Invoices also specify payment terms (when payment is due), payment methods, and tax information. They serve as a formal request for payment and a record of the transaction.

Invoices are essential for B2B transactions where payment often occurs after delivery (net 15, net 30, net 60 terms). They're also required for tax and accounting purposes, serving as source documents for accounts receivable, revenue recognition, and tax filings. In many countries, invoices must meet legal requirements for format and content.

Key invoice elements include: invoice number (unique identifier), issue date, due date, seller and buyer information, itemized line items with descriptions and prices, tax breakdown (VAT/BTW), total amount due, and payment instructions. For EU B2B transactions, valid VAT numbers for both parties are required.

Modern invoicing has moved from paper to digital, with electronic invoices (e-invoicing) becoming standard or mandatory in many countries. Digital invoices enable faster delivery, easier tracking, automated payment matching, and integration with accounting systems. Many invoices now include payment links for instant online payment.