As from two years ago (1 January 2012), CIMA members are no longer allowed to obtain direct membership from ACCA, on the basis of their CIMA qualifications.
To ensure that the high standards and integrity of the qualification is maintained, ACCA also no longer awards any exemptions at the professional level.
ACCA will, however, continue to offer CIMA members exemptions from selected ACCA modules. You can only be granted an exemption for a maximum of 9 out of the 14 papers of the ACCA qualification. The papers that you will be exempt from will depend on which CIMA papers you have passed.