What are the guarantee agencies for British immigrant visas?

I. First-level (TIER 1) immigrant visa

TIER 1 immigrant visa is introduced to attract senior talents to immigrate to the UK, and it is also the only visa that does not require the applicant to have a guarantor. There are four types of TIER 1 immigrant visas: one is high-tech immigrant visa. The British Immigration Bureau will evaluate the applicant's qualifications, previous salary and age to determine whether the applicant meets the application conditions; Second, the entrepreneur immigrant visa requires investment and entrepreneurship in the UK, or shares in existing enterprises in the UK and participates in the daily management of enterprises; Third, the investment immigrant visa, the applicant must invest in the UK and buy British government bonds or other financial products; The fourth is the graduate visa, which is issued for the temporary placement of foreign citizens who have graduated from British universities. Unlike other visas in the first-class (TIER 1) visa category, holders of postgraduate visas cannot apply for permanent residency in the UK with this visa.

Second, TIER2 immigrant visa

TIER2 immigrant visas allow British companies to hire citizens from non-EU countries to work in the UK. This visa itself does not give the applicant the right to work and live freely in the UK. It only allows the applicant to work in the employer's company and the specific position that guarantees him. TIER2 work visa can only be applied by the employer on behalf of the applicant. Although the holder cannot permanently settle in the UK with this card, it is still possible to apply for permanent residency in the UK if the relevant conditions are met.