Listing in Hong Kong or abroad must be audited by a foreign accounting firm, because foreign accounting systems are different from domestic accounting systems. Therefore, it is necessary to invite foreign accounting firms (including Hong Kong) to audit, and then publish the statements to foreign shareholders and foreign shareholders. This is a must. Since 2011, it is no longer required. Because the accounting standards of mainland China and Hong Kong have achieved equivalence. In other words, the systems on both sides are the same. Domestic accounting firms can also audit companies listed in Hong Kong. Currently, there are only 10 domestic firms with this qualification.