A CPA or firm permit holder in public practice shall not:

A CPA or firm permit holder in public practice shall not: (a) perform for a contingent fee any professional services for, or receive such a fee from a client for whom the CPA or firm permit holder performs, (i) an audit or review of a financial statement; or (ii) a compilation of a financial statement when the CPA or firm permit holder expects, or reasonably might expect, that a third party will use the financial statement and the CPA’s or firm permit holder’s compilation report does not disclose a lack of independence; or (iii) an examination of prospective financial information; or (b) prepare an original or amended tax return or claim for a tax refund for a contingent fee for any client. The prohibition in (a) above applies during the period in which the CPA or firm permit holder is engaged to perform any of the services listed above and the period covered by any historical financial statements involved in any such listed services.