304-5.4—May we authorize an employee to exceed the maximum subsistence allowances (per diem, actual expense, or conference lodging) prescribed in applicable travel regulations where we have aut

(a) Generally, yes. Subsistence allowances are usually limited to the maximum subsistence allowances (per diem, actual expense, or conference lodging) prescribed in chapter 301 of this title for travel in CONUS, by the Secretary of Defense for travel in non-foreign areas, and by the Secretary of State for travel in foreign areas. However, the maximum subsistence allowances established by this title and by the Secretary of Defense may be exceeded as long as—
(1) The non-Federal source pays the full amount of the subsistence expenses, at issue; and
(2) The subsistence expense paid by the non-Federal source is comparable in value to that offered to or purchased by meeting attendees.
(b) The maximum subsistence allowances prescribed by the Secretary of State for travel to foreign areas may not be exceeded.