monove

[tawny gulch]

Probably the easiest way to do this is through Radar

https://stripe.com/docs/radar

You could write a rule:
Block if :card_brand: = 'amex'

That would be considered a custom rule, so you'd need to be paying for Radar For Fraud Teams. Are you already using Radar For Fraud Teams?

[prime brook]

no and i dont think theyre ready to pay for that

im fine with a front-end solution

[tawny gulch]

Ah in that case you'd need to use the two step confirmation process: https://stripe.com/docs/payments/build-a-two-step-confirmation

That way you create the payment method first and can inspect the card brand prior to payment

There's the brand param: https://stripe.com/docs/api/payment_methods/object#payment_method_object-card-brand

[prime brook]

ok thank you