The COVID-19 pandemic has caused major disruptions to families' lives in many ways, including through lockdowns, social distancing, home learning requirements, and restrictions. This resulted in a rapidly changing situation where different pressures have arisen for children, young people and their families over time. Understanding the psychological effects of the COVID-19 pandemic on children and young people, through the collection of high quality data and in a way that could directly inform policy, was set out as an immediate research priority in a Lancet position paper (Holmes et al., 2020) at the start of the pandemic. The Co-SPACE study was launched on 30th March 2020, a week after the first national lockdown was implemented in the UK, with the purpose of using the findings to inform resources and support for families. To obtain a free account please register with the UKDA.