Guide

What is an Invoice?

An invoice is a commercial document that itemizes a transaction between a buyer and seller. It serves as a formal request for payment and a record of the sale.

Invoice Definition

An invoice is a document sent by a seller to a buyer that lists the products or services provided, their quantities, prices, and the total amount due. It serves as:

  • A payment request - Tells the customer how much they owe
  • A legal record - Documents the transaction for both parties
  • A tax document - Required for VAT claims and SARS compliance
  • An accounting record - Tracks income and accounts receivable

What to Include on an Invoice

Invoice Number
Unique sequential identifier for tracking
Invoice Date
Date the invoice was issued
Due Date
When payment is expected
Your Business Details
Name, address, contact, VAT number
Client Details
Customer name and billing address
Line Items
Description, quantity, and price of goods/services
Subtotal
Sum of all line items before tax
VAT Amount
15% VAT calculated on subtotal
Total Amount Due
Final amount including VAT
Payment Terms
How and when to pay
Bank Details
Account information for EFT payments

Types of Invoices

Standard Invoice

The most common type. Issued after goods are delivered or services rendered.

Pro Forma Invoice

A preliminary invoice sent before work begins. Acts as a quote or estimate.

Tax Invoice

Required for VAT-registered businesses. Must include VAT number and breakdown.

Credit Note

Issued to reduce the amount owed, typically for returns or corrections.

Recurring Invoice

Automatically generated at regular intervals for ongoing services.

Final Invoice

Issued at project completion, often following progress invoices.

South African Tax Invoice Requirements

If you're VAT registered in South Africa, your invoices must meet SARS requirements:

  • Display "Tax Invoice" prominently
  • Include your VAT registration number
  • Show VAT amount separately (15%)
  • Include customer's name and address
  • Use sequential invoice numbers

Ready to Create Your First Invoice?

Illumi makes invoicing simple. Create professional, SARS-compliant invoices in minutes.