Geneva-Annecy via bus-border crossing?

Going the other way, but I took a bus from Chamonix, France, to Geneva in June. We had to show our passports to the driver before getting on the bus. At least one couple was denied boarding. When we arrived at the Swiss border, two agents boarded the bus and looked at our passports. One woman had to go into the border office with the agents, but was back on the bus in a few minutes, and we continued on (I don’t know what the problem was).

That's similar to Broder Control when taking the train from Milan to Lugano. Thanks!

Two weeks ago, I took a bus from Geneva to Aosta, IT which crossed into France before going through the Mont Blanc tunnel to get to Italy. Entering France, 4 border agents got onboard and questioned everyone including purpose, length of staying, etc. I wouldn’t be surprised if you encounter some thing similar.

Technically, since both countries are in Schengen there is no official border crossing.

However, recently, many European countries are performing passport checks looking for anyone traveling illegally.

If a check is done, it will be done on the bus. I've encountered everything thing from a few questions to them walking by when they see me holding a US passport.

For the T272 Annecy-Geneva bus, chances are that you won't even notice a border crossing. Public transit crosses the border unhindered. For longer distance intercity buses as described by the other posters, yes, ID checks are more standard.

Long distance busses in this part of Europe are mostly used by people for whom cost trumps everything, so they are indeed popular with migrants, and therefore targeted by the border police.

But the T272 bus is just a normal public transit bus. The bus driver is not going to ask for your passport, as not everyone on that bus is expected to cross the border.