 The reasons for having a credit card declined include the relatively new issue of triggering fraud protection alerts when something just doesn't look right to the issuer. If you're planning a trip across the country or abroad, call the credit card company to alert that you're traveling outside your typical surrounds. For those who might be struggling even temporarily with finances, credit card purchases can run into trouble here too. It might be you've reached your credit limit or your card has expired. It could be you've missed payments or your credit rating has recently taken a hit.