ABC Inc. is an accrual method taxpayer. ABC's practice is to bill its customers 10 days prior to when goods are shipped, and often receives full payment prior to shipping. Realizing that it could defer a substantial amount of income at the end of the year, ABC changed its billing procedure during the year to bill customers only when goods are delivered and accepted by the customer. An IRS agent has suggested that ABC must request permission from the Commissioner before changing its tax treatment for recognizing revenue. What is your opinion