Thanks for the tips, we already started collecting evidence from the day he arrived, house insurance, sharing joined credit cards, photos, sharing expenses. Some we couldn't like same lease, my place is asking for credit check and since he is on a visitor visa can't be added but I have the emails communication with management to proof that we tried that too
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In the visitor extension, it says that you should apply before 30 days, is it ok to apply like a week or two before the expiry day?