Underwriting can take usually 3 days to a week, depending on how busy the underwriters are for that particular lender. As long as there are no sudden complications, you should be able to close in 7-10 days.nderwriting can take usually 3 days to a week, depending on how busy the underwriters are for that particular lender. As long as there are no sudden complications, you should be able to close in 7-10 days.