The Ministry of Finance official letter No. 09800558710 states: according to article 57 of Income Tax Act, after fix assets are completely depreciated at the expiration of their useful years, whether they can be charged to loss for the current fiscal year depends on whether they are destroyed or become obsolete. Accountants must make sure whether the fix assets have been destroyed or became obsolete before they make any adjustments to any related fix assets or charge them to loss in the book.