US Office Deposits
US bank deposits that are collected in domestic branches and operations (US Based). These deposits are insured by the FDIC. US banks that only have domestic operations file their call reports under FFIEC 041.
Foreign Office Deposits
Deposits that are collected in foreign branches of US banks or their operations outside of the US, and are not insured by the FDIC. These deposits are made with US bank institutions which have both domestic and international operations, and that file their call reports under FFIEC 031.
From the Federal Reserve Board:
“U.S. banks with foreign branches are expected, however, to have adequate policies to inform their U.S. customers with deposit accounts in their foreign branches that such deposits are not insured by the FDIC; that, in a liquidation, foreign branch deposits have lesser preference than domestic deposits; and that such deposits are subject to cross-border risks.