The United Nations' International Covenant on Civil and Political Rights mandates that all countries allow entry to their own citizens.
For instance, during the COVID-19 pandemic, Australia adopted a policy of denying entry to all individuals in particularly affected jurisdictions, including Australian citizens and permanent residents.
Taxation, tariff and trade rules set out what goods immigrants may bring with them, and what services they may perform while temporarily in the country.
Agricultural policy may make exemptions for migrant farm workers, who typically enter a country only for the harvest season and then return home to a country or region in the Global South (such as Mexico or Jamaica from where U.S. and Canada, respectively, often import temporary agricultural labour).
Besides that the migration legislation changes on average every six months which makes Britain not attractive for skilled migrants looking for a second nationality.
[citation needed] Eligible persons can sponsor their spouse or partner to become permanent residents, but must be able to:[27] [35] [37] [38] [40] Some commonwealth citizens have right of abode in the UK, which, for most practical purposes, gives them the same rights as British Citizens in the UK.