Albergue in St Jean pied de port Close times

I think the municipal albergue and the many private albergues will all have different policies. In general they discourage very late arrivals because many people leave St Jean very early in the morning to reach Roncesvalles that day. The albergues try to ensure that those who go to bed early have the chance of a decent night's sleep for that reason. It might be best to decide which albergue you hope to stay in and contact them directly to ask them.

The one I made reservations at asked for my arrival time and my cell phone number. As mentioned above, I think it depends on which place you stay at.

Places that serve pilgrims in SJPP are expecting to host people who arrive on the last train of the night. So yes, they will be able to accommodate your arrival. The Pilgrim's Office will also be open late enough to receive pilgrims on that last train, to find places for them to stay if they don't have reservations, and to get them set up with information and credentials for their journey. If you have a booking already, you may want to go directly to your accommodations and visit the Pilgrim's Office when they open the next morning, 7:30am.