A quote is required for call-outs, whatever the amount
In France, for any repair, call-out or maintenance job at a private customer's home, the order of 24 January 2017 (in force since 1 April 2017) requires a detailed quote before work starts, whatever the amount: hourly labour rate and estimated time, parts and their prices, travel costs, and whether the quote itself is free or paid.
Source : INC, arrêté du 24 janvier 2017 (dépannage, réparation, entretien)