EPSS is a web-based system to prepare and submit proposals for the EU Framework Programmes. It is obligatory to use this system to submit proposals.
The EPSS (Electronic Proposal Submission Service) allows proposers to create their proposal completely on-line without downloading or saving anything on their local personal computer. Access to the EPSS is specific to calls and to the corresponding subscheme. The EPSS therefore needs to be started from the participant portal / call page.
More information: https://webgate.ec.europa.eu/funding-tenders-opportunities/display/OM/Electronic+proposal+submission