National Internal Revenue Code (NIRC)
Section 234. Language in which Books are to be Kept; Translation. - All such corporations, companies, partnerships or persons shall keep the books or records mentioned in Section 232 hereof in native language, English or Spanish: Provided, however, That if in addition to said books or records the taxpayer keeps other books or records in a language other than a native language, English or Spanish, he shall make a true and complete translation of all the entries in suck other books or records into a native language; English or Spanish, and the said translation must be made by the bookkeeper, or such taxpayer, or in his absence, by his manager and must be certified under oath as to its correctness by the said bookkeeper or manager, and shall form an integral part of the aforesaid books of accounts. The keeping of such books or records in any language other than a native language, English or Spanish, is hereby prohibited.