Credit Card operates on the basis of Line of Credit.
It has nothing to do with whether you have money in your bank account or not. So a credit card payment can very well get declined even if your bank account is flush with funds.
In fact, your Credit Card Company / “Issuer” does not need to know your bank balance.
A Credit Card transaction can get declined for several reasons viz.:
- You have busted your Credit Limit
- Issuer has hotcarded your credit card since you have not paid your minimum dues.
- Your credit card has expired
- Any one or more of the plethora of systems and / or network connections involved in processing a credit card transaction are down. This is a big factor in a country like India where credit card payments are subject to Two Factor Authentication (2FA) mandate.
- You have entered credit card # and / or other details incorrectly.
The above is only a partial list. In actual practice, credit card payments can fail literally for dozens of reasons.
You can find more details at Why Two Factor Authentication Is A “Conversion Killer” & “Blood Pressure Booster”.