The four tier visa system consists of the following:
- Tier 1 - This visa category is for high-value migrants from outside the EEA and includes entrepreneurs, investors, and the exceptional talent visa. Migrants under this category do not require sponsorship but those with exceptional talent must be sponsored or endorsed by a Designated Competent Body.
- Tier 2 - This category is for skilled workers from outside the EEA with a job offer in the UK. It includes skilled workers who are transferred to the UK by an international company, skilled workers where there is a proven shortage in the UK, ministers of religion and sportspeople. All applicants under this category require a Certificate of Sponsorship (CoS) from their prospective employer.
- Tier 4 - This category is for students aged over 16 from outside the EEA who wish to study in the UK. Applicants must have a place at a registered UK educational establishment before they can apply. All applicants under Tier 4 must have a Confirmation of Acceptance for Studies (CAS) from the UK educational institution at which they intend to study.
- Tier 5 - This category contains six sub-tiers of temporary worker including creative and sporting, charity, religious workers, and the youth mobility scheme, which enables young people to work in the UK on working holidays every year. The visas are awarded to young people from countries that have reciprocal arrangements with the UK. All applicants under Tier 5 require a Certificate of Sponsorship except those who are visiting the UK under the youth mobility scheme (or working holiday visa as it is often known).