Most of the loyalty program credit cards don’t require you to keep your card to keep your rewards. For example, your Marriott Reward points remain in your account even if you cancel you Chase Marriott Rewards credit card. Your AAdvantage miles stay in your account even if you cancel you Citi AAdvantage credit card.
However, some of the credit cards from the banks that offer flexible points and miles make you forfeit your points if you cancel the card. For example, if you have a Chase card that earns Ultimate Rewards and you cancel the card without having another Ultimate Rewards earning card, you will forfeit all of your valuable Chase Ultimate Rewards points. This holds true for American Express Membership Rewards points, Citi ThankYou points, Barcalycard Arrival miles, Capital One Rewards, etc.
If you have one of these bank cards and need to cancel for whatever reason, use your points first!!!!! Either redeem them, or where applicable, transfer them to a loyalty program where your points can sit. Do not let them be forfeited!!!