41 C.F.R. § 301-11.16 – Lodging tax reimbursement.

(a) For CONUS and non-foreign OCONUS locations, lodging taxes paid by the employee are reimbursable as a miscellaneous travel expense limited to the taxes on reimbursable lodging costs.
(b) For foreign areas, separate claims for lodging taxes are not allowed because lodging taxes have not been removed from foreign per diem rates established by the Department of State.