Do I need to be a registered business to send an invoice?

No. Sole traders and freelancers invoice under their own name. Include a tax ID (VAT number, ABN, GST/HST number) only if you are registered for it.

What invoice number should I start with?

Any sequential scheme works — many people start at INV-0001 or INV-2026-001. The key is that numbers are unique and never repeat, so each invoice can be referenced unambiguously.

Do I have to charge tax?

It depends on where you are and whether you are registered. In the US you charge sales tax based on your state; in the UK, Australia and Canada you charge VAT/GST/HST only if registered. When in doubt, check with your tax authority.

How to Write an Invoice (US, UK, Australia & Canada)

An invoice is the document you send to ask a client to pay for goods or services. A clear, complete invoice gets paid faster and keeps your bookkeeping clean. This guide covers exactly what to put on an invoice and how the details differ across the US, UK, Australia and Canada.

What every invoice should include

Wherever you are, a professional invoice has the same backbone:

The word “Invoice” and a unique invoice number (sequential, e.g. INV-0001).
Your business details — name, address, email or phone, and your tax ID where you have one.
The client’s name and address (the “Bill To”).
Issue date and due date (or payment terms such as “Net 30”).
Line items — a description, quantity and unit price for each.
Subtotal, tax and total, with tax shown separately.
How to pay — bank details, card link or other instructions.

How tax and format differ by country

The structure is the same, but the tax model and a few required fields change:

United States — there is no federal invoice standard. Sales tax depends on your state and what you’re selling, so set a rate per line or mark items exempt. “Net 30” is the most common term, and Letter paper is standard.
United Kingdom — if you’re VAT-registered you must show your VAT registration number, the VAT rate (20%, 5% or 0%) and the VAT amount, with totals in GBP on A4.
Australia — a compliant tax invoice must show the words “Tax Invoice”, your ABN, the date, a description and the GST (10%). For sales of $1,000 or more it must also show the buyer’s identity.
Canada — charge GST, HST, PST or QST depending on the province, and show your GST/HST number on the invoice.

Tax rules vary by state, province and industry and change over time. Treat the figures as an aid and confirm your obligations with your accountant or tax authority.

Tips to get paid faster

Send the invoice the day the work is done — speed sets the tone.
Put the due date in plain language (“Due by 18 Nov 2026”), not just “Net 30”.
Make paying easy: include bank details or a payment link right on the invoice.
Use a clear, sequential numbering scheme so both sides can reference it.
Keep a copy. If you issued an estimate first, carry the details straight over to the invoice.

Create one in under a minute

You don’t need accounting software to send a clean invoice. Our free invoice generator builds a professional PDF with the right tax model for your country — pick US, UK, Australia or Canada and the currency, paper size, date format and tax fields are handled for you. Nothing you type is stored on our servers.