When you make a purchase with your SoFi Smart Card, the initial amount is authorized at checkout. In some cases, the final charge can be slightly higher (for example, a restaurant charge with the addition of a tip).
If that final amount is more than what’s available in your SoFi Smart Card’s Ready to Spend amount (the total amount of your SoFi Checking and Savings account balances), your Ready to Spend amount may go negative.
To bring your Ready to Spend amount above zero, add money to your SoFi Checking and Savings account or make a one-time payment to your SoFi Smart Card from an external bank account.