Marriage applications and Fiance(e)s
A spouse or civil partner of a person permanently settled in the UK must apply for a Visa at a British Consulate to join that person. Certain conditions apply :-

Both parties have to have met previously - the couple must intend to live together permanently - accommodation and income must be adequate for their support without use of public funds ;

If the couple have lived together for less than 4 years at time of application, a 2 year residence will be granted, with a requirement at the end of that time to prove that the relationship continues, and permanent residence will be given ;

If the couple have lived together for 4 years or longer, permanent residence will be given immediately on arrival in the UK.

Fiance(e) Applications

This is only available to persons living abroad and wishing to come to the UK to marry or have a civil partnership ceremony with their partner. Application is made to the nearest British Visa issuing Post and requires evidence as follows :- That the couple have previously met ; that the sponsor is a permanent resident of the UK ; that the couple intend to live together permanently after marriage / civil partnership ; that there is adequate financial support and accommodation without help from public funds, before and after the marriage.

Application while in the UK

For marriage / civil partnership in the UK when the applicant is here with another valid Immigration residence, an application for a Certificate of Approval (COA) must be made to the Home Office. If both parties are subject to Immigration residence time limits, then both have to make this application separately, and pay separate Home Office fees. The application MUST be made at least 3 months before expiry of the current residence. Visitors cannot make this application. When the COA has been granted, marriage / civil partnership can be undertaken, and an application must then be made to Home Office for residence. Two years will be granted initially, followed by permanent residence if the marriage / partnership continues, and support and income are adequate.