Over recent decades, management accounting researchers, focusing on interfirm contexts have analyzed the forms of cooperation among partners and the role played by management accounting in these contexts (Koufteros et al. 2012; Wu and Barnes 2011; Dekker 2007). Studies have showed how accounting information system (AIS) can be useful in improving the information exchange which is crucial in managing interfirm relationships (Cuganesan and Lee 2006). In doing so, some contributions have analysed how this cooperation leads partners to exchange accounting information, investigating the role of information technology (IT) in increasing supplier accountability, effectiveness and efficiency (Evans and Wurster 1997). However, to the best of our knowledge, no studies have investigated the role of AIS in facilitating buyers to effectively select their suppliers. Thus, in this paper we will investigate the role of new AIS in managing supplier selection and how it is performed (produced, modified and accepted). In doing so, we interpret AIS not just as an accounting tool which explains reality but as a boundary object which supports actors as they present their interests and facilitates the creation of alliances between them. In line with this view, we attempt to reposition, or even rehabilitate, accounting technologies in the sociological explanation (Justesen and Mouritsen 2011). Even if management accounting innovations have been examined as playing an important role in the construction or enforcement of inter-organisational processes (Vosselman 2014; Mouritsen and Thrane 2006), further research in the field of AIS is needed to give better understanding of the role played by AIS innovation in facilitating supplier selection. In doing this, we interpret AIS as a managerial tool which performs the reality through its re-presentation as creation, entailing mediation among actors involved in the supplier selection. Drawing on actor network theory (ANT) as a proper method theory (Lukka and Vinnari 2014) we carry out a longitudinal case-study at a manufacturing firm located in the south of Italy, where we examine the role of new AIS in its supplier selection from 2012 up to 2014. The case description shows how ANT offers useful insights into the interpretation of AIS as a boundary object (ideal type objects and the standardized forms), which, through accounting inscriptions, makes transactions visible, defines their ‘poles’, and provides techniques to connect them. This AIS innovation leads to the monitoring of supply performance, mitigates the emerging controversies while creating new allies, and mobilises all actors’ interests. Drawing on Busco and Quattrone (2014), we identified four major features that characterize the adoption of a new management accounting practice: its ability to provide clear visual representations of the interfirm calculable space; to create order and knowledge; to accommodate different interests through a process of interrogation and re-invention, and (4) to stimulate the engagement of all actors through participation in a series of recurrent activities. The paper is structured as follows. Firstly, we describe the management accounting innovation as a boundary object; secondly, we offer a brief literature review on AIS innovation in interfirm relationships.