Akron: Mentioned in deleted scenes (This one might not be canon because it is so far away from the others so they scrapped it
Albany: Craig, from "Valentines Day" is manager (He ignored Jan's order to fire employees)
Binghamton: Robert California closed it down when drunk and high on cocaine
Buffalo: Learn's their branch is closing during "Company Picnic"
Camden: Second worst branch after Scranton "Branch Wars"
Nashua: Holly get's transferred there
Pittsfield: Got shut down for unionizing, referenced in the episode "Boys and Girls"
Rochester: Is skipped in "Lecture Circuit" For Nashua
Scranton: Main branch in "The Office"
Stamford: Jim transfers there, Andy is from there
Syracuse: Harry Jannerone works at this branch, he tries to get Binghamton's clients after it is closed by Robert California
Utica: Karen transfer's there and become manager
Yonkers: Mentioned to have been closed during Michael's skit in "Company Picnic"