Some of the most common reasons that cause a deposit to fail are insufficient funds, incorrect card details (expiration date, CVC, billing address, etc) and the use of an expired card to add money. Please contact your card issuer directly as they might have declined our authorization request for various reasons.
We also have a daily deposit limit for recently added cards, so please wait until the next day if you have just added a new card and added money successfully with it before. This daily limit will be increased automatically after a few deposits. If you need more funds before your limit has been increased, you can add money via bank transfer.