Tax residency rules and definitions vary by country and apply to both individuals and businesses.
Tax residency for individuals
In most cases, you’re a tax resident in the country where you live and work. If you file a tax return or pay taxes there, you’re likely considered a tax resident.
Some countries determine tax residency based on how long you stay there. For example, in the UK, spending 183 days or more in a tax year makes you a UK tax resident.
It’s also possible to be a tax resident in more than one country at the same time. This is called dual residency.
Tax residency vs. citizenship
Being a citizen of a country doesn’t always mean you’re a tax resident there. However, the US considers all its citizens tax residents, no matter where they live.
Tax residency for businesses
A business is usually a tax resident in the country where it’s incorporated and managed. If these are in different countries, the business might have dual residency.
For more details, check the OECD website.