JustInvoice Guides
What to Include on an Invoice: A Checklist for Freelancers and Small Businesses
Updated · By the JustInvoice team at PrismCode Labs
A missing due date or a vague line item is one of the most common reasons an invoice gets paid late. Clients need enough detail to approve and pay it without writing back with questions. Here is everything a professional invoice should include.
The invoice checklist
- The word "Invoice" at the top, so it can’t be mistaken for a quote or estimate.
- A unique invoice number. Number invoices in sequence (for example INV-0042) so each one can be referenced and none are skipped.
- Issue date and due date.
- Your details: business or trading name, address, email or phone, and your tax registration number if you have one.
- Client details: their name or company name and address, plus a contact person if it’s a company.
- Line items: a clear description of each product or service, the quantity or hours, the rate, and the line total.
- Subtotal, any discount, tax (with the rate shown), and the total due.
- Currency, especially for international clients.
- Payment terms and methods: when payment is due, how to pay, and any late-payment terms you have agreed.
- An optional thank-you note or reference, such as a project or purchase-order number.
Taxes vary by country
Rules about what an invoice must show for VAT, GST or sales tax differ between countries, and some apply only once you are registered. If you charge tax, check your local tax authority’s invoice requirements, or ask an accountant.
Invoice vs estimate vs receipt
- An estimate (or quote) is sent before the work, saying what it will probably cost.
- An invoice is sent after the work or delivery, asking for payment.
- A receipt confirms that payment was received.
JustInvoice creates both invoices and estimates, so you can quote first and invoice once the job is approved.
Mistakes that delay payment
- No due date, or terms the client doesn’t understand.
- Vague descriptions like "Services" with no detail.
- Sending to a general inbox instead of the person who approves payment.
- Arithmetic errors in totals or tax.
- Duplicate or missing invoice numbers.
Let an app fill in the details
JustInvoice covers the checklist automatically: it numbers invoices, calculates tax, discounts and totals, remembers clients, and lets you choose the currency per invoice. Finished invoices export as professional PDFs in Classic, Modern or Minimal templates. Read next: how to make an invoice on iPhone.
Frequently asked questions
What information is required on an invoice?
At minimum: an invoice number, issue and due dates, your details, the client’s details, a description of each item with its price, the total due, and payment terms. Tax rules may require more, such as your tax registration number.
How should I number my invoices?
Use a unique, sequential number for every invoice, such as INV-0001, INV-0002. An invoice app can number them automatically.
What is the difference between an invoice and an estimate?
An estimate is sent before work begins to say what it will likely cost. An invoice is sent after the work to request payment.
What payment terms should I use?
Common terms are due on receipt, 7 days, 14 days or 30 days. Whatever you choose, show the actual due date on the invoice.
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