Hi!
So, I am a bit confused about how the Common App system works on letter of recs for transfer students. If I request a letter from someone, do I need to request it once or request it through every single school. Thanks in advance!
All schools 
Teachers only have to fill out one letter though.
You submit a request for each school individually under their recommendation tab. But its a very simple process that only requires their basic information. At least its simple on our end, not sure about the recommenders side. One of my professors completed the request within two days, the second has been MIA for a few weeks now.
If all your schools are listed on the Common App that makes it more convenient. Georgetown kind of caught me off guard since they have a separate application and recommendation process.