Apple Daily Cash Balance into Apple Savings Account?

This is easy to do in the iPhone and funds added from Apple Cash are generally credited instantly.

Deposit money into Savings

When you open Savings you agree to automatically deposit Daily Cash that you earn into your Savings account.3 You can also add money to Savings from a linked external bank account or from Apple Cash. 

1. On your iPhone, open the Wallet app and tap Apple Card.
2. Tap Savings account, then tap Add Money.
3. Enter the amount that you want to add, then tap Add.
4. Select or add the payment source that you want to add money from.
5. Double-click the side button to confirm with Face ID, Touch ID, or your passcode.

Money that you deposit into Savings starts earning interest on the day that the transfer is initiated from the Wallet app.

If you transfer money from Apple Cash, the funds are typically available instantly. If you transfer money from a linked external bank account, it will generally take a few days for funds to be available for withdrawal.

Set up and use Savings in Apple Wallet - Apple Support

Step 4 above select Apple Cash as source of funds. You may need to verify your identity if you’ve not previously done so for Apple Cash.

Identity verification for Apple Card or Apple Cash - Apple Support