Use the OCC address of the District that supervises your institution. See this link:
http://www.occ.treas.gov/district.htmIf you are supervised under the Community Bank Supervision program, use the "geographic district" address (i. e. Northeastern, Southern, Central or Western - District Office).
If you are supervised under the OCC's Midsize or Large Bank Supervision programs, you use a "Washington, D. C." address. Contact your bank's examiner-in-charge for the correct address for midsize and large banks.
See Appendix B to Part 25 for the sample notices (Main Office and Branch Office).