Rarely you may see problem cases with the following scenario:
user's profile in your dashboard has an indication that a payment card is saved on his profile;
user's Activity section however shows no card verification fee being charged;
user has most probably made a top-up once, usually with the smallest available option on your service;
he has made one ride only and gone into debt;
when you check your Stripe merchant account and look for this user, you can see that there is no verified payment method saved for this user on Stripe side.
Why does this happen?
The user starts going through the card verification/adding process on Stripe, does not complete the 3DS step in Stripe window, however from Stripe we receive a webhook stating the card is successfully verified.
This lets the user top up afterwards and make a ride, as Stripe SDK allows to a add card without any minimum payment and from ATOM side we are unable to force this.
What do we recommend?
Make sure you have configured your account as follows:
set Wallet payment scheme;
set a minimum amount to start a ride;
prohibit using bonuses only to start a ride or purchase a subscription;
make sure to set auto top-up options;
make sure to set up a wallet balance at which vehicle needs to be automatically stopped.
More information on how to limit fraud using your dashboard options on ATOM here:
https://support.atommobility.com/en/articles/5422624-limiting-fraud-and-debtors