When your payment processor identifies a high-risk order, ReCharge will send you an automated notification alerting you of the potential fraudulent charge. ReCharge receives the initial notice directly from the payment processor, so you will need to log-in to you payment processor account to assess the risk and decide if you would like to proceed with fulfillment or reject the charge.
A charge that is marked as fraudulent will be held in your account until you approve or reject the payment. If you receive the notice of risk, it is important to take action on the charge before fulfilling the order created in Shopify. If you choose to reject the charge, you will want to cancel the order in Shopify either through the Shopify Admin or directly in ReCharge.
Each payment processor provides their own fraud analysis tool for use. If you would like more information on how your payment processor identifies fraudulent orders, you can visit the Stripe, Braintree, or Authorize.net Help Center. For general information on fraud prevention best practices, Stripe offers some tips on how to best protect your store from fraud and disputes.