To earn interest* on your savings, you need to be at least 18 years old, have a Cash App Card, and be using a personal account, not a Cash for Business account. When you meet those requirements, you can earn the highest interest rate available for your savings by direct depositing at least $300 in paychecks each month. If you have a Cash App Card and don’t meet all of these requirements, you can still transfer money into savings and earn interest at a lower rate.