There are many reasons why transfer failed when adding money to Cash App, including expired cards or insufficient funds. In most cases, you will need to contact your bank to find the reason for the error. You should also make sure that all of the card details are correct. If all of this fails, you may try repeating the transaction.

• The first reason Cash App transfer failed is if your card is declined or blocked. If your card is declined, you will get an error message. You should contact your card issuer to resolve this problem. If the card has been blocked, your transaction will only be possible once you clear it.
• Another possible reason for a Cash App transfer to fail is insufficient funds. If your card needs more funds, you should check your account's balance and then try again. 
• Make sure that the card is linked to your bank account. Also, make sure that the account is not linked to a VPN. Occasionally, these VPNs can cause issues when using the Cash App.
• If you have tried adding money to the Cash App but received an error message, your device might be outdated. If it is, it's a good idea to update your device.
• To do this, open Google Play Store, go to Settings, About Phone, and System Updates. Afterward, restart your device. You should try reinstalling the Cash App if you still need help with this.