I'm Zuzanna, from the team here at Shopify :)
Great question! The best way to do that would be with an app. Apps are like extra features that you can add to your stores. In this case, the app you'd want to try is Fraud Filter, check it out here. It lets you create specific rules in your store that will stop certain people from being able to complete orders. You can see more details about the app and how to set it up on this page of our Shopify Manual.
I hope this helps! If you have any more questions or concerns feel free to reach out to us here :)
Have a great one,
This app works for physical products but not digital downloads. Is there a way to make the Fraud Filter cancel orders before the moment payment goes through? I want to be able to block certain past customers and I mainly sell digital attachments. I have set up some Fraud Filter rules that work to cancel orders however, the cancellation doesn't happen until AFTER the payment has gone through so the customer is still receiving the digital attachment as they are set up to auto fulfill. The customer is still getting a copy of the digital attachment on the order confirmation screen and also in email and then Fraud Filter is canceling the order but it's too late, the "bad" customer has already received the digital download link/file so it's not really helping my situation. This example happened specifically with a customer that used Paypal Express checkout. It seems to me the app should be able to run its "Fraud rule check" prior to Shopify fulfilling line items since digital attachments can be automatically fulfilled. I would not have the time to manual fill my orders.
I just need a way to block customers from purchasing and I cannot figure out a way to stop that digital attachment from being sent regardless. I do not want to set up manual fulfillment either. Any other app or options would be great.
Another thing I noticed when reading the How To on Fraud Filter is it states when you have selected the option to cancel an order that meets one of the rules you define, Fraud Filter will make the customers receipt state that their card has been declined but this isn't happening either. I have tested it and the order still goes through for payment and then after that payment is processed, the order is flagged and canceled within Shopify. Again, the digital attachment is still being sent to customer.