Yes for the tools, which are free: the Bilan Carbone® V9 method, emission factors from ADEME's Base Empreinte and ADEME spreadsheets are accessible without a licence. Yet they account for only about 20% of an assessment's value. The rest depends on internal time and expertise, meaning 30 to 80 person-days for a first scope 1, 2 and 3 assessment in an SME, equivalent to a budget of €15,000 to €48,000 depending on company size. For most SMEs, this hidden cost exceeds the price of an external service.
Read the source article: Doing your own Bilan Carbone®: tools, time, limits