The typical reasons for this are wrong credit card details, insufficient funds, or transaction limit exceeded. In some cases this is due to the card issuer blocking the transaction on your behalf, for fraud protection purposes.
If you received a failed transaction notification, please try placing your order again. If you're still unsuccessful please contact the card issuer (their number is usually on the back of the card) and ask them to permit an authorization from JetBrains / Adyen (our payment processing partner).
Alternatively, you can try a different card or one of our other payment options.