Depending on your browser and if you have not deleted your cache, the firm information that you entered on the initial pay page may reappear the next time you go to the Web Pay Page to pay your account. However, none of the information related to the credit card (i.e. credit card number, expiry date, etc.) will appear.
If you prefer to enter your credit card information only once and store it in a secure payment page, consider switching to the credit card payment method.