European Court of Auditors’ annual report: personnel costs remain the main source of errors in research projects

The European Court of Auditors has published its annual report for the 2025 financial year. In the budget heading “Single Market, Innovation and Digital”, which includes Horizon 2020 and Horizon Europe, the estimated error rate was 2.9%, remaining above the 2% materiality threshold.

In research expenditure, auditors identified quantifiable errors in 28 of the 90 transactions examined. Personnel costs were the most common source of error, including claims for time not spent on the project or not adequately supported by records. Despite the simplifications introduced under Horizon Europe, the audit found no significant differences in the regularity of expenditure compared with Horizon 2020.

The Court also examined lump sum funding. In the projects audited, it identified shortcomings in the assessment of proposed budgets and unclear definitions of some deliverables and activities, making it difficult to verify the completion of work packages. It recommends more consistent budget checks and clearer rules for grant reductions where work is only partially completed. The report also notes that the audited proposals predated some of the more recent improvements to the Commission’s guidance.

The Court further reviewed controls to prevent plagiarism and double funding. It found the Commission’s SIMBA tool, which checks project proposals for similarities, broadly fit for purpose, while recommending that the associated procedures be better formalised.

European Court of Auditors’ annual report 2025