They say:
We are carrying out a value for money study on whether the child maintenance system is delivering value for money for children, separated parents and the taxpayer. A brief description of the scope of our work can be found here.
To help us with our audit, we would like to hear from you about your experience of the Child Maintenance Service (CMS). This consultation will be open until midday, Friday, 30 July 2021. We are aiming to publish our value for money report towards the end of 2021.
naosurvey.nao.org.uk/s3/Child-Maintenance-Service