We use multiple methods to examine how depletion and auditors’ skeptical dispositions interact to affect auditors’ challenging of managers in negotiations over financial statement amounts. We expect auditors are likely depleted from effortfully exercising self‐regulation during the busy times when these negotiations occur. Individuals in a depleted state tilt toward natural, less effortful behaviors. Thus, we posit that the effects of depletion will diverge depending on the auditor's skeptical disposition―a determinant of how natural or effortful they will find the skeptical behaviors (e.g., challenging) versus client service behaviors (e.g., maintaining the client relationship and audit efficiency) required for negotiations. We predict that client service auditors (i.e., low skeptics) will challenge managers less in negotiations when depleted versus non‐depleted, while high skeptic auditors will challenge more when depleted. We test this interactive prediction in an abstract experiment where we manipulate depletion and measure auditors’ skeptical dispositions using trait skepticism. Findings support our predictions. We also develop a new measure of auditors’ client service–skeptic disposition based on the skepticism literature that adds nuance to the traditional lower versus higher skeptic labels. In a second study, interviews with audit partners validate the realism of our depletion and client service–skeptic constructs and corroborate our experimental findings. Our study sheds light on depletion effects in auditors’ negotiations with their clients and how the effects differ based on auditor personalities.This article is protected by copyright. All rights reserved.