April at the national level, is one of the months with the highest fiscal activity by the Annual Declaration of Natural Persons and at the same time, it is an invitation to investigate the reforms, updates and new legislation in force that, after a few months, could have economic consequences when declaring taxes.

This is the case of the so-called “ certain date “. Although, it is not a new concept since it has existed in Civil Law for a long time; During the month of December 2019, the Supreme Court of Justice published in the Federal Judicial Weekly, Thesis: 2a./J. 161/2019 (10a.) its application in the tax field.

This should private tax documents need a certain date for them to be valid .

“…con la finalidad de otorgar eficacia probatoria a los documentos privados y evitar actos fraudulentos o dolosos en perjuicio de terceras personas. Así, la “fecha cierta” es un requisito exigible respecto de los documentos privados que se presentan a la autoridad fiscal como consecuencia del ejercicio de sus facultades de comprobación…”

Thesis: 2a./J. 161/2019 (10a.)

When is a certain date considered?

Based on the same thesis, the certain date is considered in any of the following cases,

  • when they register in the Public Registry of Property
  • from the date they appear before a notary public
  • from the death of any of the signatories

The application of this new legal framework in tax matters (despite the fact that it protects the tax authority or other taxpayers from fraudulent acts) will currently have an impact on the cost of operation and speed in the conclusion of contracts, policies and other documents that must be certified with a certain date , required by the tax authority during the verification.

Alternatives? – Conservation records

Conservation records are digital documents that certify the signing of a document at a specific time and date , as it is a completely digital process based on security standards homologous to the Electronic Signature, (this is the case of NOM-151-SCFI-2016) for which the conservation records, are valid as a document with certain date .

Even though this sounds like the obvious solution, the main difficulty lies in the fact that at the time of writing, there is no public service that issues conservation records .

Currently, there are only suppliers who provide this alternative by volume of operations, which could significantly reduce the bureaucratic process, but not the cost.


Therefore, we inform you that this new legislation will apply to private documentation, which has implications in the tax declaration.

Given that the current policy to combat Tax Fraud and Evasion will continue to tie up loose ends, we invite you to contact us to review your situation and advise you in your annual statement, analyzing, among other things, if you could be affected by the ‘ certain date ‘.

It will be a pleasure to assist you in your 2019 annual declaration and project in advance, the current financial year 2020.