Once the introductory rate ends, whatever balance remains will revert to what's known as the revert rate. The revert rate is typically either the purchase rate or cash advance rate. The same revert rate typically applies to whatever introductory rate a card offers. For example, a card has an introductory balance transfer rate, which reverts to the cash advance rate. You transfer $5,000 of debt and pay off $4,000 during the introductory period. The cash advance rate will apply to the $1,000 that remains for as long as it remains.