BMO Platinum Credit Card Annual Percentage Rate (APR) for Purchases 0% introductory APR for 15 months from account opening date. After that, your APR will be 16.49% to 26.49% based on your creditworthiness. This APR will vary with the market based on the Prime Rate. Loss of Introductory APR: We may end your introductory APR and apply the standard APR if you make a late payment. Promotional/Introductory Rates and Your Grace Period: If you take advantage of an offer with an introductory or promotional APR, we will charge you interest on new Purchases, unless your new Purchases have a 0% APR, or you pay your Statement Balance, including any Balance Transfers and Cash Advances, in full each month by your payment due date.