This seems very bad, I'm assuming this applies to all customers whether businesses or not, so here are a few potential gotchas I see-

1. You sell to an individual who is not in the country that their payment information is related to and is not delivered to that country, do you charge VAT based on the payment information alone or do you have to physically verify that they are in the country claiming the VAT?

2. Prepaid CC can have false information, how do you determine is it is true so you can charge the right VAT?

3. Fraud, if you sell something to a fraudster, do you have to find out which country the fraudster was in to determine VAT you owe after the fact?

4. What about Bitcoin transactions where no location information is known?