Mortgage Contingency: There are really three ways to make an offer on a co-op. All cash, which is the most attractive to sellers; a purchase with a mortgage so that the buyer can apply for a mortgage but still has to go through with the deal (or lose the downpayment) regardless of whether the buyer can get the mortgage or an offer with a mortgage contingency, meaning that the buyer can cancel the deal and get back his or her deposit if the mortgage doesn’t come through. If you absolutely need the mortgage to close, make sure your offer is with a mortgage contingency.
With a condo, you are down to two choices. All cash or mortgage contingency.