This study investigates the changes in proxies of financial reporting quality such as deferred and discretionary income as well as earnings management according to IFRS 15, ‘Revenue from contracts with customers’, which was fully adopted in 2018. An important change in the new revenue recognition standard is to allow the recognition of revenue for the portion of the consideration received for goods or services in which the performance obligation has been satisfied. Accordingly, it is expected that the discretionary judgment of the management to distinguish between the amount of revenue and the portion of deferred revenue, which is a liability for performance obligations, among the consideration received for the supply of goods or services is expected to increase. When discretionary revenue recognition increases, it means that managers may intentionally change the size of deferred revenue or decrease the likelihood of recognizing discretionary revenue. The empirical results are as follows. First, the deferred revenue decreased significantly due to the change in the revenue recognition standards. Second, the size of discretionary revenue measured in various methods and the level and size of the accrual earnings management measurement have significantly decreased. This study suggests that managers are actually applying discretion, such as reduction of deferred revenue, when applying the new revenue recognition principles. This result is useful in that it supplements the case study of the existing revenue recognition principles. In addition, the results of this study suggest that continuous monitoring of various stakeholders such as auditors, regulatory authorities and investors on the performance obligation of revenue recognition is necessary, and that it is necessary to present a process in which the management objectively recognizes the consideration received for goods or services.