But UK residents who are not domiciled in the UK - usually because their fathers were not British - are liable for tax on their overseas income and gains only if they are brought into the UK.

The tax varied by region, and in some areas, residents also had to buy a minimum amount of salt.

Under Spain's favourable tax laws, temporary non-Spanish residents are taxed at 24%, with minimal social security contributions, as compared to the top rate of 43% for Spanish nationals.