Within the NHS health check (NHSHC) programme, there is evidence of marked inconsistencies and challenges in practice-level self-reporting of uptake. Consequently, we explored the perceptions of those involved in commissioning of NHSHC to better understand the implications for local and national monitoring and evaluation of programme uptake. Semi-structured, one-to-one, telephone interviews (n=15) were conducted with NHSHC commissioners and leads, and were analysed using inductive thematic analysis. NHSHC data were often collected from practices using online extraction systems but many still relied on self-reported data. Performance targets and indicators used to monitor and feedback to general practices varied between localities. Participants reported a number of issues when collecting and reporting data for NHSHC, namely because of opportunistic checks. Owing to the perceived inaccuracies in reporting, there was concern about the credibility and relevance of national uptake figures. The general practice extraction service will be important to fully understand uptake of NHSHC.