P.R. Laws tit. 21, § 5219
(a) Omission of assets.— In case [assets] valued at twenty five percent (25%) or more of the taxable value were omitted in the tax return, the tax may be appraised by the Collection Center, or a court procedure may be commenced for the collection of said tax without an appraisal, within a period of six (6) years after the tax return was filed.
(b) Fraud or lack of a return.— In case a false or fraudulent return is filed with the intention of evading taxes, or in case the return is not filed, the tax may be appraised by the Collection Center, or a court procedure for the collection of said tax without an appraisal may be commenced at any time.
(c) Waiver.— When prior to the expiration of the statute of limitations established in § 5218 of this title or subsection (a) of this section for the revision of the personal property tax return, the valuation of the properties, the tax computation made by the taxpayer, and for the collection of said tax, the Collection Center and the taxpayer have agreed in writing to appraise the personal property and the tax after such a period, the tax may be appraised at any time prior to the expiration of the term agreed to. The term thus agreed to may be extended by successive written agreements made prior to the expiration of the term previously agreed to.
(d) Collection after appraisal.— When the appraisal of the personal property and the tax levied by this title has been made by the Collection Center within the proper prescription term for the same, said tax may be collected through legal proceedings for collection in court, provided they commence:
(1) Within seven (7) years after the appraisal of the tax, or
(2) prior to the expiration of any term for said collection agreed to in writing by the Collection Center and the taxpayer before said seven (7)-year term has expired. The term thus agreed to may be extended by successive agreements made prior to the expiration of the term previously agreed upon.
History —Aug. 30, 1991, No. 83, § 6.19.