This research aims to examine and analyse the effect of Auditor Independence, Workload, Task Complexity, Persistence, on Audit Deficiencies with Professional Scepticism Moderation. Furthermore, this research also aims to identify the background of what causes audit deficiencies during the audit process. This research uses primary data in the form of questionnaires. The sample in this research was 308 external auditors from Public Accounting Firms (KAP). The data is processed using the Smart-PLS4 application. The results show that (1) Auditor Independence and Persistence hurt Audit Deficiencies. (2) Workload and Task Complexity have a positive effect on Audit Deficiencies. (3) Professional Scepticism can moderate the influence of workload and persistence on audit deficiencies. (4) Professional Scepticism is unable to moderate the influence of auditor independence and task complexity.  This research suggests that workload and task complexity can increase the potential for audit deficiencies when auditors carry out the audit process in the field. Where workload and task complexity have a direct positive and significant impact on audit deficiencies. Carrying out appropriate workload allocation and carrying out task complexity analysis can minimize the potential for audit deficiencies. Meanwhile, auditor independence and persistence have a negative and significant impact on audit deficiencies. When becoming an auditor, a person is required to be independent and have high persistence, especially in terms of completing work well according to procedures when conducting an audit.