The simplification of EU research and innovation funding has been on the agenda for many years, with industry, academia and researchers across Europe seeking simpler administrative rules, better communication with the European Commission, legal certainty and consistency. With Horizon 2020, the Commission introduced changes designed to simplify the rules in this area. Our audit examined whether these changes have been effective in reducing the administrative burden for beneficiaries. We concluded that the majority of the simplification measures have been effective, although not all actions produced the desired result and opportunities to improve still exist. Beneficiaries need more user-friendly guidance and tools, and the Commission has to further test the appropriateness and usability of new funding schemes. Stability in the rules is also important and, while beneficiaries are able to adapt to complexity, frequent modifications to guidance can cause confusion and uncertainty.