Abstract Monitoring and Verification (M&V) was reviewed in this journal in 2015 as part of the Special Issue to mark the tenth anniversary of the IPCC report on CCS. This article provides an update, focusing on identifying areas where there has been technical progress. Activity in CCS has continued since 2015, but the shift towards commercial utilization has altered the context for M&V. Published field experimentation, and verification with monitoring methods, has not progressed as much as was hoped. While much high-quality theoretical work has continued, especially in the area of the design of monitoring systems, an imbalance is apparent. One area where field tests have continued, and progress has been marked, is the rapid development of distributed acoustic sensing and its pairing with permanent seismic sources. Progress here has the potential to make seismic monitoring cheaper and less intrusive. Interesting proposals have been made for monitoring with pressure data, but most have not been tested. Methods of monitoring in the marine ecosystem are rapidly being adapted to the requirements of M&V. These methods are well adapted to the quantification of leakage that is mandated in some jurisdictions. Overall, the need for testing the numerous good ideas in field experiments is very apparent.