Invoice Requirements by Country: US, UK, Canada & Australia Compared (2026)

Sell to clients in more than one country and the same question keeps coming back: does my invoice need to look different for each of them? The reassuring answer is that the core of an invoice is nearly identical everywhere — the differences sit almost entirely in the tax rules. This guide puts the US, UK, Canada and Australia side by side so you can see, in one place, what every invoice must contain, the income level that forces you to register for tax, and the tax number each country expects to see on the page.

The fields every country agrees on

Before the differences, the common ground. Whatever your client's country, tax authorities expect the same basic anatomy on an invoice, and getting these right covers most of the requirement everywhere:

• A clear label — the word “Invoice” (or “Tax Invoice” in Australia) — and a unique, sequential invoice number.
• Your business name, address and contact details.
• The client's name and address.
• The issue date, and ideally a payment due date.
• An itemised description of the goods or services, with quantities and unit prices.
• The amount before tax, any tax shown separately, and the total amount due.

Miss one of these and you create work for the person paying you, in any jurisdiction. The country-specific rules below are layered on top of this shared base — they don't replace it.

Tax-registration thresholds at a glance

The single biggest difference between countries is the income level at which you must register to charge sales tax, VAT or GST. Below the threshold you generally don't charge the tax; above it you must register, charge it, and hand it over. Here is where each country draws the line:

• United States: there is no national sales tax and no single threshold. Each state sets its own rules, and many use an economic-nexus threshold — commonly US$100,000 in sales or 200 transactions into that state — before an out-of-state seller must register.
• United Kingdom: you must register for VAT once your taxable turnover passes £90,000 in any rolling 12-month period, the figure HMRC has held since April 2024.
• Canada: you stop being a “small supplier” and must register for GST/HST once your taxable revenue exceeds C$30,000 in a single calendar quarter or across four consecutive quarters.
• Australia: you must register for GST once your annual GST turnover reaches A$75,000 (A$150,000 for non-profit organisations).

Thresholds change with budgets and policy, so confirm the current figure on the official page before you rely on it: gov.uk for the UK, the ATO for Australia, the CRA for Canada, and the IRS for US federal matters (sales tax itself is administered by each state).

What tax number goes on the invoice

Once you're registered, your invoice usually has to display a tax identifier. The name of that number is different in each country:

• United States: businesses use an Employer Identification Number (EIN) from the IRS; sole proprietors often use their Social Security Number instead. There is no US “VAT number”.
• United Kingdom: a VAT registration number, shown only once you're VAT-registered. Your UTR is for HMRC records, not for invoices.
• Canada: your GST/HST account number, which forms part of your CRA Business Number (BN).
• Australia: your Australian Business Number (ABN), which belongs on every invoice — more on why below.

United States

The US is the outlier: no federal sales tax and no VAT. Sales tax is set by states and even local districts, so whether you charge it depends on what you sell and where your customer is. Since the 2018 Supreme Court decision in South Dakota v. Wayfair, states can require even out-of-state sellers to collect tax once they pass an economic-nexus threshold. For most freelancers billing services the practical answer is often “no sales tax”, but it varies by state, so check your state's Department of Revenue. See our guides for 1099 contractors and invoicing US clients from abroad, or start from the US invoice generator.

United Kingdom

UK invoices follow HMRC rules. Below the £90,000 VAT threshold you issue a simple invoice with no VAT. Once registered, you must issue a full VAT invoice showing your VAT number, the rate applied to each item, the VAT amount, and the totals with and without VAT. The full breakdown is in our UK invoice requirements guide.

Canada

Canada layers a federal GST with provincial taxes: 5% GST in some provinces, a harmonised 13–15% HST in others, and a separate QST in Quebec. Below C$30,000 you're a small supplier and don't have to charge GST/HST at all; above it you register, charge the rate for your client's province, and show your GST/HST number. Full detail in invoice requirements in Canada.

Australia

Australia has the strictest identifier rule. If you carry on an enterprise you should quote your ABN on every invoice, because without it the paying business is generally required to withhold 47% of the payment under the ATO's no-ABN withholding rule. GST of 10% applies once you pass the A$75,000 threshold, and a compliant document must be headed “Tax Invoice”. The specifics are in our Australian tax invoice guide.

Billing across borders

One rule is consistent across all four countries: exports of goods and services to overseas clients are usually zero-rated or GST/VAT-free, meaning you don't add your local sales tax to a foreign customer's invoice. The mechanics differ — and digital services sold to overseas consumers can be an exception — so confirm your situation with the relevant authority. If you're a freelancer in one country billing clients in another, the key is to show your own tax details correctly and state the currency clearly on the invoice.

The takeaway: build one solid invoice that nails the universal fields, then adjust a single layer — the tax registration and the tax number — for each country you bill. Do that and the same document works whether your client is in New York, London, Toronto or Sydney.