Okay, if there is a registered form of marriage in the Ghana then you will have to obtain this in order for him to apply for a spouses visa so that he can stay here permanently I'm afraid. If you marry and register then he can apply for a spouses visa using Form VAF4 and submit it to the British Embassy in Ghana.
He may visit the UK on a 6 months visa, which he can apply for online from the British Embassy as well provided he can show:-
1. That he wants to visit the UK for no more than 6 months
2. That he intends to leave at the expiry of the 6 month period
3. That he has enough funds available to support himself during his stay without the need to access public funds.
4. That he does not intend to undertake paid or unpaid employment.
Please note that if he is here he cannot make an application for a spouse visa from this Country. If he wishes to make an application then he will have to return to Ghana to do it from there. The UKBA will simply not entertain an application made on a visitor's visa.
He should also not overstay an visitor's visa he obtains because this could have an impact on any future application he may choose to make.
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