Fundamental and applied research at ILL across the range of scientific domains addresses major societal challenges for the environment, clean energy, climate change, health, and information and communication. This knowledge-generation and low technology-realisation-level reasearch is the starting point of a long process from science through innovation to market. The scientific infrastructure at ILL is used by more than 100 European companies over a ten-year period in a range of industry sectors for their R&D work, enabling essential new products and processes to reach market. The implementation of the upgrade programmes at ILL increases the performance and competitiveness of the companies specialized in precision mechanics, vacuum and engineering, neutron guides and neutron choppers. Technologies developed by ILL and in partnership with companies are often subsequently used by other national and international facilities and laboratories. The economic impact due to the implantation of the ILL in Grenoble is very important for France and the Auvergne-Rhône‐Alpes region in terms of activity and direct and indirect employment.

The principal service offered by ILL is access to the world's most intense neutron beams and state-of-the-art instrumentation and scientific infrastructure. ILL's service is designed to be comprehensive, accompanying researchers through the full scientific process from ideation to experiment and scientific outcome, usually publication. This entails close collaboration between ILL staff and researchers in the user community, as well as providing additional, dedicated services, for example for sample preparation and characterisation, and data treatment and analysis, including simulation and theory. Access is mainly physical (in-person) but full remote access has been continuously developed, in particular since Covid, and now enables high-quality, remote participation. Access is gained through regular, open application rounds with excellence-based selection adjusted to take into account the financial contributions of stakeholders. Specific services are offered to industry users who can access the ILL in the same way as academic users for pre-competitive research, or avoid the peer review process and open data requirements by paying for proprietary access, which can include consultancy.