My husband and I will be arriving in Paris on a Friday. We plan to buy a Navigo Decouverte and use carnets until Monday when the Navigo is valid. My big question is, should I wait until Monday to buy the Navigo, or if i buy it on Friday, will it automatically start on Monday, or will I be paying the Navigo price for Friday-Sunday and then have to recharge it again on Monday?
Thanks in advance for your help.
You can't buy a Navigo for the current week on Fridays. They will sell you next week's validity. Don't worry. Get it at a convenient time between when you arrive and Monday morning.
Buy it when you get to town and are buying your RER ticket into the city or your first carnet. Get it all done at once; they will charge your kit with the following week and you can assemble it at the hotel at your leisure.