If you do not wish to charge the guest credit card, but would like the system to pre-authorize the guest card at the time of booking, you can enable the “Authorize Only (for web booking)” option.

When it’s enabled, the system will pre-authorize the configured amount to the guest card. No actual charge will be made. If the authorization is successful, the system will proceed with the reservation, otherwise, the reservation will not be made.

As shown in the screenshot below, you can set the amount to be authorized by selecting the Authorization Type. For example, if you only wish to check if the credit card number is valid at the time of booking, you can select the “Authorize a percentage of the full amount” option, and enter “0” for the “Partial Authorization Percentage(%)” field.