If you are non EU national and you are married to a British or settled person in the UK then you can obtain a spouse visa to join your spouse.
Once applicants apply for spouse visa they will be granted 33 months and if their situation remains the same after 33 months they can extend their visa, and eventually after 5 years applicants can apply for indefinite leave to remain.
If applicants are not married then they can apply for fiancé visa of which the requirements are almost similar to those for spouses with some slight variation in norms. For successful fiancé application initially applicant will be granted 6 months visa and they show that they have plan to get married within this 6 months.
Requirements for spouse visa are:
-Being 18 or over.
-The relationship should be genuine.
-Settle or British person in the UK must show he/she has adequate accommodation for his/her partner.
-Marriage certificate / proof of relationship for unmarried partners / wedding plan for engaged couples.
-Applicant must prove proficiency in English by passing an approved English test with a score of at least CEFR level A1.
-Financial requirement: settle partner must prove that he/she is earning £18,600 per year.