Disclaimer up front: I'm a software developer, not a tax advisor, and tax rules change frequently and vary by jurisdiction. This article gives you the general shape of how sales tax, VAT, and GST work so you know what questions to ask — always confirm specifics with a local accountant before you finalise how you handle tax on your invoices.
That said, understanding the basic differences between these three systems will save you from a lot of confused invoice-related emails.
Sales Tax (United States)
Sales tax in the US is charged once, at the point of final sale to the end consumer, and the rate varies by state — and sometimes by city or county within a state. Unlike VAT or GST, sales tax is generally not charged on business-to-business services in most states; it mostly applies to tangible goods and certain specified services.
As a freelancer providing services (design, development, writing, consulting), you most likely won't need to charge sales tax unless your state specifically taxes your category of service, or you're selling a taxable digital product. The concept of "nexus" — having a sufficient business presence in a state — determines where you're required to collect tax. If you only have clients in other states and no physical presence there, you typically don't need to register or collect tax in that state.
Because sales tax doesn't cascade through a supply chain the way VAT does, it's usually a simpler (though state-by-state inconsistent) system for service-based freelancers to navigate.
VAT (United Kingdom, European Union, and Many Other Countries)
VAT — Value Added Tax — is charged at every stage of a supply chain, with businesses able to reclaim the VAT they paid on their own purchases. The end consumer effectively bears the full VAT cost, while VAT-registered businesses pass the tax through and reclaim what they paid.
If your annual taxable turnover exceeds your country's VAT registration threshold (in the UK, £90,000 as of 2026), you're required to register for VAT, add it to your invoices at the applicable rate (usually 20% in the UK for standard goods/services), and file regular VAT returns. Below the threshold, you can register voluntarily but aren't required to.
For cross-border B2B services within the EU, the "reverse charge" mechanism often applies — meaning you invoice without VAT, and the business client accounts for VAT on their end instead. This is a common point of confusion for freelancers invoicing EU clients, so confirm with an accountant whether reverse charge applies to your specific situation.
GST (Australia, Canada, India, and Others)
GST — Goods and Services Tax — works similarly to VAT in concept (a multi-stage consumption tax with input credits for registered businesses) but the specific rates, thresholds, and rules vary significantly by country. Australia applies a flat 10% GST once you exceed the registration threshold (AUD 75,000 annual turnover). Canada has GST at the federal level plus separate provincial sales taxes in some provinces, creating combined rates that vary by where your client is based. India's GST system is notably more complex, with multiple tax slabs and specific rules for export of services.
If you're invoicing clients in any GST country, the registration threshold and applicable rate depend entirely on the specific country — there's no shortcut here beyond checking the current rules for that jurisdiction or asking a local accountant.
What About Withholding Tax?
Separate from sales tax, VAT, or GST, some countries require the client to withhold a percentage of your payment and remit it directly to their tax authority on your behalf — common when a client in one country pays a freelancer in another. This is distinct from VAT/GST entirely; it's a mechanism for collecting income tax, not consumption tax. If a client mentions withholding, ask specifically whether it relates to income tax (withholding) or VAT/GST (consumption tax) — the paperwork and implications are completely different.
Practical Advice for Invoicing Across These Systems
- Always state your registration number on the invoice if you're VAT or GST registered — this is usually a legal requirement, not optional.
- Show tax as a separate, clearly labeled line item rather than folding it into your rate, so the client can see exactly what's being charged and why.
- If you're not registered for VAT/GST and not required to be, it's fine — and often expected — to simply state "No VAT applicable" or omit the tax line, rather than leaving it ambiguous.
- When in doubt, ask the client what they need. Corporate clients with established accounting departments often know exactly what tax treatment your invoice requires, especially for cross-border payments — and asking upfront avoids a corrected invoice later.
How Invoice Pro Lab Handles Tax
Invoice Pro Lab lets you add tax as a percentage on individual line items or on the invoice total, label it however your jurisdiction requires (VAT, GST, Sales Tax, or a custom label), and it calculates the totals automatically. You're responsible for knowing the correct rate and registration requirements for your situation — the tool handles the maths, not the tax advice.
Add the right tax label and rate to your next invoice — create one with Invoice Pro Lab, free and ready in minutes.