FYI The essential difference between an assertion-based examination engagement and a direct examination engagement is that: (1) a written assertion from the responsible party is required for an assertion-based examination engagement, whereas such an assertion is not obtained for a direct examination; and (2) the practitioner may report on either the assertion or the underlying subject matter for an assertion-based examination engagement, whereas the practitioner reports only on the underlying subject matter for a direct examination engagement.

For an Assertion-Based Examination Engagement—Request a Written Assertion about the Subject Matter From the Responsible Party If the Engaging Party Is the Responsible Party and Refuses to Provide a Written Assertion—The practitioner should withdraw when that is permitted. If the Engaging Party Is Not the Responsible Party and the Responsible Party Refuses to Provide a Written Assertion—The practitioner need not withdraw but should disclose that refusal in the practitioner's report and restrict the use of the report to the engaging party. **The responsible party is still responsible for the subject matter as a whole, and the practitioner should request a written assertion covering the entire relevant period(s), even when the responsible party was not present during some (or all) of the period covered by the practitioner's report.**