stemming pandemic-driven uncertainty. The payment industry is rapidly prioritizing digital transformation to stay competitive [3]. Therefore, as firms embrace these new changes, we will become more engaged and aligned with their customer payment journeys.  
The benefits of using digital payment technologies go beyond convenience. Digital payments expand the potential customer base for merchants, reduce cash-handling costs and bring many informal shadow economies to the fore, increasing tax revenues for governments. All of these factors and other advantages of using digital payment technologies can help in reducing economic friction [5]. As a result, overall spending and consumption will be increased, leading to greater production, an increased number of jobs, higher wages and economic growth [6]. However, despite the numerous benefits, there are a lot of challenges associated with digital payment technologies. For example, the payment industry seems to be burdened with an increased risk of privacy [7], cybersecurity, fraud and other threats [8; 9]. The security breaches and lack of knowledge about payment technologies among users are some of the primary concerns for individuals and organizations [10]. Furthermore, the need for infrastructure modernization and digital transformation has been highlighted together with a call for attention to banks' navigational strategies in light of new risks and 'unpredictable and unforeseen' situations, such as the COVID-19 pandemic [3].  
Although there are many existing studies on digital payments addressing various issues (e.g., business model [11; 12], technological infrastructure [13; 14], technology adoption [15; 16]), there is a lack of research, which provides a comprehensive synthesis and a universal classification of digital payment technologies and associated challenges. For instance, there are some forms of payment technologies referred to in previous studies [15; 17; 18]. Nevertheless, these studies concentrate on a single mode of payments. For example, the classification by [PERSON] et al. [17] is on blockchain technology-based cryptocurrencies and [PERSON] et al. [18] is on mobile payments. Furthermore, the challenges associated were mostly mentioned as part of the adoption studies. For example, [PERSON] and [PERSON] [15] emphasized challenges in mobile payment technologies in emerging economies and [PERSON] et al. [19] studied issues related to the adoption of e-payment systems. Thus, this study aims to bridge these gaps, provide an overall picture and a state-of-the-art overview of the widely dispersed knowledge on the emerging digital payment technologies and their challenges and answer the two over-arching research questions: _(1) What are the emerging digital payment technologies and (2) what are the challenges associated with them?_  
The remainder of this paper is organized as follows. The next section presents the research background, including the definition of digital payment technology and other related terms used in the review context, as well as related work, which identifies the research gap and rationale for this review. The methodology is covered in Sections 3 and 4 is devoted to the findings and discussions. In Section 5, the limitations of the study with some recommendations for further work are presented and Section 6 contains the conclusion.