We summarise the recent reflections of five thought leaders in the field of routine outcome measurement (ROM) for psychological therapy, and then add our own experience of introducing a national ROM system in the UK. We highlight, in particular, the post-implementation challenge of securing data of sufficient reliability to help inform service quality improvements. We ground our conclusions and recommendations in the rapidly evolving discipline of implementation science, and offer a best practice model for applying research recommendations in practice settings. In this context we portray ROM implementation as significant organizational change that benefits from rigorous process and clearly defined, well-communicated targets.