U.S. CPA should have a working knowledge of IFRS because Multiple select question. in a U.S. company that owns foreign subsidiaries, a U.S. CPA might need to convert the IFRS financial statement of a foreign subsidiary to U.S. GAAP. U.S. companies might be owned by foreign entities for which a U.S. CPA might need to use IFRS to prepare a reporting package. a U.S. company might own subsidiaries located in the U.S. that prepare financial statements using U.S. GAAP