Tiered interest is when you're paid an interest rate based on the tier that your account balance falls into. Interest is then calculated on your whole account balance. Let us show you how tiered interest works with the below example:
$0 - $1,999 X%
$2,000 - $24,999 Y%
If there's $30,000 in an account that pays tiered interest then Z% is paid on the whole account balance.