Learn about per diem interest, how it's calculated, its role in loans like mortgages, and why it's essential for borrowers to understand before closing a loan.

Editor's Note: APYs listed in this article are up-to-date as of the time of publication. They may fluctuate (up or down) as the Fed rate changes. CNBC Select will update as changes are made public.

Robin has worked as a credit cards, editor and spokesperson for over a decade. Prior to Forbes Advisor, she also covered credit cards and related content for other national web publications including ...

Unless you're taking advantage of an intro 0% APR offer, if you carry a balance on your credit card, you're likely being hit with high interest charges. The average APR for all credit card accounts is ...