Now in its 30th year, the Unlinked Anonymous Monitoring Survey is a vital tool for harm reduction, says Emily Phipps. This year the Unlinked Anonymous Monitoring Survey (UAM) of people who inject drugs celebrates its 30th anniversary in England and Wales and 18th anniversary in Northern Ireland, making it the longest running annual survey of this cohort in the world. Coordinated by Public Health England (PHE), the survey consists of a self-completed questionnaire and biological sample that is anonymously tested for HIV, hepatitis B and hepatitis C to monitor trends in blood-borne viruses (BBVs) and behaviours that impact transmission, such as needle sharing, testing and treatment uptake. No identifiable information is collected, and the survey or test result cannot be traced back to an individual, making it easier for us to ask questions about risky behaviours that might otherwise go unanswered. The UAM is a powerful tool for advocacy and service planning, both nationally and locally. Each centre undertaking more than thirty surveys each year is provided with a free, detailed report of their responses to help them understand what the key priorities for their clients are. Nationally, the report feeds in to key annual publications such as Shooting up and Hepatitis C in the UK. The survey data is also shared internationally with the World Health Organization and European Centre for Disease Control to support global BBV elimination initiatives. In current times, championing the needs of people who inject drugs and ensuring continued access to services is incredibly important. There are valid concerns that reduced uptake of BBV testing and difficulties in delivering the same level of needle and syringe provision during the pandemic will lead to an increase in infections among this group. The UAM, now more than ever, is an essential tool for understanding the impact of COVID-19 on people who inject drugs, and to keep track of progress as services recover. The UAM team would like to say a huge thank you to all of our volunteers and participants who have been undertaking the survey during the last few difficult months \u2013 the data you have collected is absolutely vital. If you would like to join the UAM survey, or have taken part previously and would like to restart, the UAM team would love to hear from you. Every survey completed is a hugely valuable source of information on this population group who are otherwise often under-represented in policy and statistics. For further information, please contact Claire Edmundson, at email@example.com. Dr Emily Phipps is consultant epidemiologist at the National Infection Service, PHE. She prepared this work with Megan Bardsley, HIV\/STI surveillance and prevention scientist, and Claire Edmundson, senior scientist, at PHE \u2018We have had a phenomenal number of responses to the Unlinked Anonymous MonitoringSurvey, which provides us with a wealth of information about our clients \u2013 the addition of a finger-prick test for the anonymous blood sample part gives us another opportunity to offer diagnostic testing. Through this testing done alongside the survey, we have picked up 47 cases of hepatitis C that we may not have done otherwise.\u2019 Louise Hansford, regional Hepatitis C elimination coordinator.