Via dei Fori Imperiali 1
This tourist info point and ticket office sits between the Colosseum and Piazza Venezia.
Tickets for Via dei Fori Imperiali 1
In the same area
Must sees in Rome
We traveled to the main station in Rome so that we can activate it,
It was not possible in another part of Rome, this is what we were informed from the Metro station. But we had the best experience with it, and we cut the lines and was a good think for our pockets :D
It seems that there is no way to verify it on a bus unless you come across a ticket officer on duty.