It's unusual to tax non-resident citizens (the U.S. is almost unique there), but it's common to tax foreign income of residents. For example, the UK also taxes

It's unusual to tax non-resident citizens (the U.S. is almost unique there), but it's common to tax foreign income of residents. For example, the UK also taxes residents on their worldwide income: https://www.gov.uk/tax-foreign-income/overview https://www.gov.uk/tax-foreign-income/overview