PurposeThis paper aims to assess the effect of different leadership types, the client's identity and auditors' self-confidence on auditors' impartiality.Design/methodology/approachThis paper is a descriptive-survey type, and the collected data are based on a predesigned questionnaire distributed in January 2020. The PLS software is used for data analysis, and the statistical population of this paper includes employed auditors in enlisted audit firms on the Official Association of Auditors. When the parameters were insignificant, the obtained probability from the model fitting was used for hypothesis testing, and the appropriateness of the model was assessed via the structural equations.FindingsThe results show a significant relationship between charismatic, transformational, participatory, delegating and bureaucratic leadership and auditors' impartiality. There is also an association between the client's identity and the auditor's impartiality. The client's identity mediates the relationship between transformational leadership and the auditor's impartiality. Moreover, there is a significant relationship between self-confidence and auditor's impartiality.Originality/valueThis paper enjoys an innovative method in the field of behavioural auditing. The effect of transformational leadership on auditor's impartiality with the mediatory role of the client's identity shows the in-depth client–auditor relationship has been taken for granted and not examined previously, so the results of this paper can lend a helping hand to audit firms to enhance the organisational performance.