The article analyses the ways in which technology and law disperse, channel and reassemble agency in ICT-enabled legal proceedings. It works from case studies of online civil claims in England and Italy, and the automatically issued speed camera fine process in Australia. Information and communication technologies affect legal procedures in three dimensions: legitimacy, efficacy and performativity. The law can legitimate ensembles of technological and performative procedures, but it cannot construct them by regulation. Technology is a distinct regulative regime that opens some channels of communication while closing others. Machines and software codes identify and admit participants and direct human activity. The focus on the performative explores the requirements of sense-making, by which participants recognise the context and the legal consequences of ICT-enabled procedures. The interfaces of law and technology rely on the interpretive context in which messages are understood as well as the legal forms in which they are transmitted. Each of these elements is essential to the circulation of agency between people and things that reassembles and constitutes legal and social relationships.