The interest rate for a credit card is listed on the monthly statement or bill for the card, and it's noted on the initial documentation received when the account was opened. Consumers can also contact the issuer for the rates.
Credit card issuers are legally required to make disclosures to card holders. The Truth in Lending Act in the United States requires that card issuers disclose the interest rate for the card in the "Schumer box" on the card application. All issuers must use the same calculation for determining the annual percentage rate (APR) they display on card documentation in order to maintain compliance with federal law.