Section 81 : To maintain records or documents:
1) Each person who is liable to pay tax pursuant to this Act has to maintain in Nepal the following necessary documents, in addition to the documents required to be maintained in the format or type as prescribed by the Department or to be certified or authenticated by audit or in other manner:

a) Necessary information and documents supporting the income returns or any other documents required to be submitted to the Department pursuant to this Act,

b) Documents assisting to assess the tax payable by him

c) Documents supporting the deduction of expenses.

2) Except as otherwise specified by the Department by issuing a notice in writing, the documents referred to in this Section have to be safely retained for at least Five years from the date of expiration of the concerned income year.

3) In cases where any document referred to in Sub-section (1) is not in the Nepali or English language, the Department may, by issuing a notice in writing, require the concerned person to submit the translated version of such document in the Nepali language done, at such person's own cost, by a recognized translator under the law in force.