Centurion Black Card Interest Rate

For transactions added to pay over time balances at your request (Select & Pay Later), AMEX charges interest from the date they are added to a pay over time balance until they are paid.

For transactions added automatically to a pay over time balance (Sign & Travel and Extended Payment Option), AMEX charges interest from the transaction date until they are paid. However, AMEX will not charge interest on these transactions if:

Your Pay Over Time Previous Balance for the billing period is zero; or

You paid the Account Total Previous Balance for each of the previous two billing periods in full by the closing date shown on their respective statements
AMEX calculates interest for a billing period by first figuring the interest on each balance. Balances within each feature-such as Select & Pay Later, Sign & Travel and Extended Payment Option-may have different interest rates.

AMEX calculates the interest by using the Average Daily Balance method (including new transactions) to figure interest charges for each balance. The total interest charged for a billing period is the sum of the interest charged on each balance. 

Centurion Interest Rate

:  The interest charged for a balance in a billing period, except for variations caused by rounding, equals:

Average Daily Balance (ADB) x Daily Periodic Rate (DPR) x number of days the DPR was in effect. 

ADB (Average Daily Balance): To get the ADB for a balance, AMEX will add up its daily balances. Then they divide the result by the number of days the DPR for that balance was in effect. If the daily balance is negative, we treat it as zero.

DPR (Daily Periodic Rate):.  A DPR is 1/365th of an APR, rounded to one tenthousandth of a percentage point.
Each Centurion Black cardholder has their own specific interest rate.  Interest rates are based on creditworthiness, credit history, and other quantitative factors.  The more risky the credit card holder, the greater their interest rate will be.  The interest rate is only for cardholders that hold a Carry-Over / Pay-Over-Time balance from prior months.

The Centurion Credit Card interest rate is variable and can flucuate depending on the prime rate.  AMEX uses the Prime Rate from the Money Rates section (or successor section) of The Wall Street Journal.  The Prime Rate for each billing period is the Prime Rate published in The Wall Street Journal 2 days before the Closing Date of the billing period.

If the prime rate does increase then the Centurion variable interest rate credit card will also increase.  This means that cardholders may have to pay more in interest then in the past.
Black Card Requirements