An invoice is a request for payment and, often, a tax record. Getting the details right means you get paid faster and your bookkeeping stays clean. Here's what to include, in plain English.
Add up an invoice with discount, tax and delivery using the free Invoice Total Calculator.
The essentials on every invoice
- The word "Invoice" and a unique, sequential number (INV-0101, INV-0102...). Never reuse or skip numbers casually; your records should be easy to follow.
- Your business details: name, address, email and, if you have one, your tax or registration number.
- Your customer's details: name, company and address, plus their purchase-order number if they gave you one.
- Dates: the invoice date, and the due date or payment terms such as "14 days".
- Line items: what you supplied, quantity, unit price and line amount.
- Totals: subtotal, any discount, tax if you charge it, and the total due.
- How to pay: bank details or a payment link, and what reference to use.
Requirements vary by country, especially for sales tax and VAT. If you're registered to charge tax, your invoice may need extra details. This guide is general information, not tax or legal advice; check your tax authority's rules.
Work out the total in the right order
Apply discounts before tax. A $1,000 subtotal with a 10% discount is $900; tax at an example 8% adds $72; $25 delivery makes $997 due. Whether delivery is taxed depends on local rules.
Deposits, receipts and credit notes
Ask for a deposit invoice before larger jobs. When you're paid, a receipt confirms it. If you need to reduce an invoice you've already sent, issue a credit note that references the original rather than editing it.
Track what's outstanding
Sending invoices is half the job. Keep a register with each invoice's due date and payments received, and check the aging weekly: current, 1-30 days late, 31-60 and so on. A useful health check is days sales outstanding: receivables ÷ credit sales × days in the period. $8,000 outstanding on $20,000 of credit sales over 90 days is 36 days. The free Days Sales Outstanding Calculator works it out.
Follow up politely, early
Send a friendly reminder a few days after the due date, with a copy of the invoice attached. Most late payments are forgotten, not refused. The Small Business Invoice & Receipt Pack includes a reminder template alongside the invoices.
This guide is general information, not tax, legal or accounting advice.