The Grant Agreement is certainly a heavy, demanding and sometimes confusing document especially to newcomers in Horizon 2020 projects. Nevertheless, you should read it carefully and make sure you understand it since all the rights and obligations you have towards the EC are described there.
Each specific action has its own Grant Agreement, so you will find different documents for:
- European Research Council (ERC)
- Marie-Sklodowska-Curie (MSC)
- SME Instrument
- ERANET Co-fund
- Pre-Commercial Procurement (PCP)/Public Procurement of Innovative Solutions (PPI)
- European Joint Programme Co-fund
- Framework Partnerships
However, all the above are based on the two General Model Grant agreements (for multi-beneficiary project and for sole beneficiary), but with specific clauses. To help beneficiaries demystify these legal documents, the EC has prepared an Annotated Model Grant Agreement with extensive explanations, different use cases and examples. Although the sheer volume of it (748 pages) can be intimidating, it is the best available source of information for Project Implementation under Horizon 2020. The General Purpose GA has 7 chapters and 58 articles. Depending on the action some of them do not apply.
You can download the General Annotated Model Grant Agreement (V4.0 – 21.04.2017) here.