Okay, we have rented a house for 4 years and are now buying. We need to have the electricity/gas/water/phone turned on, but there is a 6 week gap between our signing and when we move and we don't want to cut our supply here, so I guess all we can do is open a 2nd electricity/phone account? We haven't ever had a contract with GDF, so that should be pretty simple and although it says you can apply online for a contract if you haven't ever had one before, you then have to set up an online account area, the first piece of info being demanded? You guessed it- an account number.
My other question is where does one go to sign up for water service? I have googled it and can't seem to debrouille (franglais!) where to find it.