With the Introduction of Appendix V - Immigration Rules for Visitors - the category of marriage visit visas was introduced which has created some confusion between this form of entry clearance and that of fiancée . For those seeking to enter the UK with a view to settling in the UK with their spouse, then there should be no doubt that a fiancée visa route is to be pursued ( with all that Appendix FM entails ). But for those who have no immediate intention of residing in the UK or no intention at all, then entry clearance in terms of Appendix V ( V6 ) should be sought.
This category is also beneficial for those whose proposed spouse is not settled in the UK but who perhaps are here in some other capacity yet wish to marry in the UK whilst here eg : students / workers .
To qualify for this visa, the standard requirements of Appendix V ( V4.2 - V4.10 ) MUST STILL BE MET ie : genuinely seeking entry for no longer than 6 months, intend to leave at the end of the visit, do not intend to take employment, sufficient funds to maintain and accommodate whilst present in the UK without recourse to public funds etc. In addition , in terms of V6, one need to be over 18 years of age and free to marry.
The marriage visit visa is granted for 6 months after which time you MUST depart the UK. You cannot seek to extend your stay or apply to Home Office to vary status to that of a spouse in terms of the Immigration Rules. Any such application would be met with a mandatory refusal.
The Home Office guidance is fairly helpful in practical terms.