Questions and responses on finder.
If you frequently experience overdrafts in your account, consider looking into a checking account that offers overdraft protection.
Trying to do this will automatically result in a declined transaction.
When Test Mode is turned off, the merchant will attempt to process all transactions they receive.
As you mentioned that your card has remaining balance but has a pending transaction means that there may be a floating amount on your account and this may have taken up the remaining balance of your card.
Check this before making your purchases to ensure you have enough funds.