Visa invitation letter – registration with stolen credit card details

We’ve encountered problems with people using stolen credit card details to make payments, presumably to receive invitation letters from us. All these registrations are from the same country. This issue still persists, even after we deactivated access to the visa and author invitation letters.

Do you have any idea how we can handle this problem? Are there any mechanisms you can recommend to avoid credit card fraud for our event?

Currently the name of the card holder cannot be checked by the credit card networks.
Accordingly, your acquirer / gateway won’t be able to perform a name check.

You can ask if the 3-D Secure / Verified by Visa security system is available for your account (additional costs may be incurred). Both systems feature additional security authentication that prompts the buyer to enter a password or number that is known only to the bank of the card holder and the card holder themselves. Since the merchant does not know this password and is not responsible for capturing it, it can be used by the issuing bank as evidence that the purchaser is indeed their cardholder. Usually this eliminates the risk of "unauthorized transaction" chargebacks, but at the same time many users still experience problems with this function.

There is another function provided by ConfTool that also might help you.
ConfTool has the option to prevent online payments from users from selected countries .

Please go to:
Overview => Settings => Manage Payment Options
...and enable the "Expert Settings" (click on the cogwheel icon on the bottom of the page). Then scroll to the section "Payment by Credit Card", subsection "Enter Credit Card Details Online" and for the option "Prevent Online Payments for Certain User Groups" enable either "Prevent online payments for users from Africa" (if you don’t expect any legitimate registrations from outside your country or area) or enable "Prevent online payments for users from countries where the 'Special Payment Option' is set" if you want to select the countries causing these problems yourself (see Image 1).

Via the IP address, any ConfTool installation can determine the country of the participant when the person creates a user account.

Consequently, users from these countries cannot access the online payment system, but will see the fax payment form instead, have to fill in that form, and then send it to you. This will prevent them from trying out several cards. Usually they don't even try to fill in that form and send it, as they realize it's not worth the hassle and there are other easier targets for their fraudulent activities.

To edit the countries where the "Special Payment Option" is enabled, please go to:
Overview => Settings => Settings for User Registration => Manage the List of Countries => Edit Country Details
... and enable the "Expert Settings" again. Now, please select the country you want to edit and click on the button "Edit Country Details". On the following page please enable the option "Special Payment Option for this Country?" (see Image 2).

Further information on this topic is available on the page Visa invitation letter - immigration fraud.