1. Please make sure you have entered the correct card number. 

2. Check that you have money in the account. 

3. Make sure your card is open for online purchases.
Since EU have rules about payment verification (SCA), you might need to verify your purchase with a third party verification.

If it still doesn't work, please contact your bank.
If you have more questions, contact us at happytohelp@onceupon.se.