Do all accounts have to be audited by COA?

Yes, the COA has “the power, authority, and duty to examine, audit, and settle all accounts pertaining to the revenue and receipts of, and expenditures or uses of funds and property, owned or held in trust by, or pertaining to, the Government, or any of its subdivisions vested under 2(1) Article IX-D of the 1987 Philippine Constitution.