A fiancé visa is a UK immigration route that allows a foreign national to enter the country to marry or enter into a civil partnership with their British or settled partner. It is usually granted for six months, during which the couple must marry or formalise their relationship. After the marriage or civil partnership takes place, the visa holder can apply to switch to a spouse visa, enabling them to live and work in the UK. This visa requires proof of a genuine relationship, meeting financial requirements, and fulfilling English language criteria.