1) The provider suspects you will not be able to repay the funds you are borrowing. (credit score changed)
2) If the provider suspects there is fraudulent use of the card.
3) If the provider suspects there is unauthorised use of the card.
4) If the provider suspects security details of the credit card have been compromised.
5) If the customer has not or will not agree to new account terms.
6) If the customer has stopped using the card for a prolonged period of time.
7) If the customer has issued bad cheques to the provider to pay off their balance on more than one occasion.
8) If the customer is going bankrupt or
9) If the customer has provided false credit information.
10) The card issuer has decided to cancel that particular card for all customers.
If a provider has canceled a credit card then they will typically still charge interest on any funds which are owed. In summary, generally a card is canceled if the provider views a customer as having significant risk of not repaying credit or is not using the card.