Qusetion: Credit card companies typically charge an annual fee to each credit cardholder for a package of benefits and services, including access to a revolving line of credit. The fee becomes due and payable when posted to the cardholder's account. Assuming the fee usually covers a period extending beyond the end of the credit card company's current taxable year, when is it included in gross income? Does it matter if the fee is refundable on a pro rata basis when a cardholder closes the account during the period covered by the fee? Explain with references to primary sources.