Short answer: usually where you live, not where your clients are. Most countries tax people on where they are tax resident, so a freelancer living in Portugal with clients in the UK normally pays income tax in Portugal. Three things can change that answer: the residency rules of the countries you spend time in, tax withheld at source by some countries, and US citizenship, which follows you wherever you live.

Residency decides, not where your clients are

Income tax follows the person. Each country has its own test for who counts as tax resident, and residents are usually taxed on their income from everywhere. Where your client sits rarely decides it on its own.

The tests look at more than a day count. The UK's statutory residence test is a good example of how detailed they get. Spending at least 183 days in the UK in a tax year makes you resident automatically. But you can also become resident on far fewer days if you have enough ties to the UK: a home there, family there, work there, or a pattern of past years spent there. Our UK statutory residence test Guide walks through every test, and the law itself is in Finance Act 2013, Schedule 45.

The "183-day rule" is mostly a myth

Many freelancers believe that staying under 183 days somewhere means they owe that country nothing. It is a useful number, but it is rarely the whole test. Countries look at where your home is, where your family lives, and where your working life is centred. You can be under 183 days and still resident, or resident in two countries at once, which is where treaties come in.

When your client's country taxes you too

Your client's country can still take a share in a few situations:

Tax withheld at source. Some countries deduct tax from payments to freelancers before you are paid. India's tax deducted at source is a common one; see our India freelancer TDS Guide.
A fixed place of business there. Working regularly from an office or base in your client's country can create a taxable presence there.
US citizenship. The US taxes its citizens and green card holders wherever they live, so an American freelancer abroad files a US return as well. The IRS explains this on its page for citizens abroad.

Double tax treaties stop you paying twice

When two countries both have a claim, a double tax treaty between them usually decides who taxes first. The other country then gives credit for the tax already paid. The credit is rarely automatic: you claim it on your return, and you need the paperwork from the other side to do it.

VAT is a separate question

Income tax and VAT follow different rules. When you sell services to a business client in another country, you often do not charge your own VAT at all. Under the reverse charge the client accounts for it instead, and your invoice needs to say so. Selling to consumers abroad, or selling digital products, works differently; our post on the EU's €10,000 rule for online sellers covers that side. For the invoicing detail, see our cross-border invoicing Guide.

A quick check before your next invoice

Where are you tax resident this year, and could a second country claim you too?
Is any client's country withholding tax from what it pays you?
Do your invoices need VAT, reverse-charge wording, or neither?
If you are a US citizen, are you filing a US return as well?

If you cannot answer one of these with confidence, that is the one to sort out before the tax year ends.

Questions people ask us

Do I pay tax in my client's country if I never go there?

Usually not, unless that country withholds tax at source on payments to freelancers. Your income tax is normally due where you are resident.

I move between countries every few months. Where am I resident?

Possibly nowhere obvious, possibly in two places at once. Each country applies its own test, and a treaty may break the tie. This needs working out year by year, before you cross a line rather than after.

Do I charge VAT to a client in another country?

For services to a business client, often not: the reverse charge usually moves the VAT to them. The answer depends on where you and your client are and what you sell.

Want this handled for you?

This is exactly what we do for freelancers working across borders: we work out where you owe tax, set up your invoicing and registrations, and file your returns. AI does the routine work and an accountant is responsible for it. Book a free 30-minute call.

General information, not advice on your situation. Tax rules change and depend on your facts; check your position with a qualified professional before you file or pay.