Marriage Visitor Visa:
If you want to do marriage or register a civil partnership in the UK, you want to notify for marriage or civil partnership and you do not want to live or settle in the UK after your marriage or civil partnership, then you must apply for a marriage visitor visa. If you want to convert your civil partnership into a marriage, then you do not need a marriage visitor visa.
You also do not need a marriage visitor visa under the EU settlement family scheme, Irish nationals, and decisions pending on the EU settlement family scheme. You must enter a marriage or civil partnership contract within 6 months after you arrive in the UK. The application will be filed online, proved your identity and a decision will be made within 3 weeks on your application. You must be 18 years of age or above for a marriage visa, in a real relationship. You can do or support yourself in the UK on this Visa.