The report aims at identifying deficits in the interplay of the ⁠REACH⁠ processes registration, evaluation, authorisation and restriction and points out potential obstacles in meeting the regulation’s goal of achieving a high level of protection in an efficient way. The interfaces between the processes registration, dossier evaluation, substance evaluation, authorisation and restriction are described and analysed with regard to the intended interactions, existing instruments to support the interplay, and observed deficits.  Based on this, the main findings on the deficits and options to improve the interplay are summarised.