Manual Credit Card Collection - Potential Problems
Older payment modules like credit card and CEON Manual Card are not recommended for the following reasons:
- they are not PCI Compliant
- storing credit card details in your database means both the store owner and the customer are at risk in the event of a breach.
- it may no longer be legal to do this (depending on your jurisdiction)
- it may be a violation of your merchant agreement (depending on the terms you agreed to).
So what should you do?
- 
Switch to one of the built-in payment gateways. There are many payment processors Zen Cart supports. 
- 
Switch to one of the payment gateways from the Plugins Library. 
The former will be better supported of course, but it’s your choice.
Notes:
- 
Many gateways can be configured to Auth Only instead of Auth and Capture if your concern is that the final order total might change. 
- 
The plugin Authorize.net CIM Card on file allows you to securely retain card information for future charges. 
All these options give you a credit card entry form on your checkout payment page, which is what most customers will expect. (Naturally they all require an SSL certificate, but hopefully you already have one; if not, install SSL first.)