This work deals with the highly practice-relevant problem of automated contract conclusion through so-called M2M applications in the field of electronic procurement. It combines technical basics, technical terms and practical fields of application with legal considerations on the modernisation of the doctrine of legal transactions. Based on the insights gained, various contract models for the use of automated systems are presented and modified for M2M transactions in e-procurement. Following on from the proposed attribution instrument of the "system declaration", rules for framework contract and platform models are conceived for the legal structuring of M2M transactions.