If you boyfriend has overstayed his visa then he can be deported.
Overstaying your visa is a general ground of refusal which means that they can deny him a visitor's visa if he applies for one from his country.
If you have ILR or are a UK citizen then you could make applicaiton based on your relationship (including unmarried partner's visa, fiance visa or spouses visa) can only be made once you are both 21 years of age. They are very strict on this and will not entertain any such applicaiton until he is 21.
Unfortunately you must have been co-habiting for two years in order to apply for an unmarried partners visa.
Once he is 21 you can apply for a fiance visa to marry here, or you can travel to his country to get married and then he apply for a spouses visa to the UK embassy near to where he is. In order to be eligible for a spouses visa:-
- 1. That you are legally married to eachother (marriage certificate)
- 2. You are present and settled in the UK (eg. Passport, proof of accommodation)
- 3. You intend to live permanently together here in the UK as husband and wife (statements, evidence of her (statements, correspondence(
- 4. You can support each other withoutthe need for public funds (bank statements, evidence of income)
- 5. You have suitableaccomodation which is owned or lived in only by you or your household and where you and your dependents can live without any help from public funds (tenancy agreement, land registry docs if you your own home)
- 6. That neither of you are younger than 21 years of age. (birth certificates, passports)
The criteria for fiance visa is very similar but you woudl have to show that you intend to marry once he is here.
You will need to apply for settlement (ie. spouses visa) by using form VAF4 Settlement, available for download from UKBA's website.
If you do not have ILR or are not a UK citizen please advise me and I shall revise my answer appropriately.
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