What to Put on an Invoice: A Checklist for Freelancers

According to Glowbug’s checklist, an invoice needs ten things: the word Invoice, your details, your client’s details, a unique number, the date, a due date, itemized lines, the totals with tax, how to pay, and the currency.

A clear invoice gets paid faster, because nobody has to email you back with a question. Use this list for every invoice, whatever app or template you make it in. Rules differ by country, so if you charge sales tax or VAT, check what your tax office requires on top of this.

The checklist

Write lines your client recognizes

“Website design, 12.5 hours at $80” is easy to approve. “Services, $1,000” invites a question. Use the words from the quote or the project, list hours or quantities, and add a project name or purchase order number if your client gave you one.

An example

Invoice INV-0042 · Issued 12 November 2026 · Due 12 December 2026
From: Your Studio, hello@yourstudio.example
To: Harbour Labs, 210 Pier Avenue, Portland, OR
Website design: 12.5 hours × $80 = $1,000.00
Total due: $1,000.00 (USD), by bank transfer to the account below.

Common mistakes that delay payment

• No due date. Without one, your invoice joins the “when we get to it” pile.
• Sending it to the wrong person. Ask who pays invoices; it is often not the person you worked with.
• Missing payment details. Every extra email costs days.
• A line with no price. Or a total that doesn’t add up. Check before you send.
• Waiting to send it. Invoice when the work is delivered, while it is fresh.

The faster way: Invoicewell

Invoicewell is a Mac app for invoices and quotes that fills most of this list in for you, and won’t call an invoice ready until it is:

• Filled in for you. Your business details (set once), the next invoice number, the client’s address, their payment terms and due date, your tax rate and your usual rate.
• Checked before it goes out. Your business name, a client, something to bill and a price on every line, or it tells you what is missing.
• Or just ask. Tell Claude or another AI assistant “Invoice Harbour Labs for this month’s work”, and it asks only what it can’t know. You press Send.

Invoicewell runs on macOS 14 or later and costs $19.99 once.

FAQ

Does an invoice need an invoice number?

Yes. A unique number lets you and your client refer to it and keep records straight. Most people number invoices in order, such as INV-0001, INV-0002.

What is the difference between an invoice and a receipt?

An invoice asks to be paid; a receipt confirms that payment was received. Many freelancers send an invoice first and a receipt or paid invoice afterwards.

What payment terms should a freelancer use?

Common terms are due on receipt, 14 days or 30 days. Shorter terms get paid sooner; whatever you choose, write the actual due date on the invoice.

Do I have to put my address on an invoice?

In many places a business address is expected or required, especially when you charge tax. Check your local rules; at the least, include a way to contact you.

Can I invoice a client in another currency?

Yes. Agree the currency first and state it clearly on the invoice. Invoicewell lets you set a currency for each client.