
Image: Public domain (Canada)
In a blog post I wrote last year after a couple of delightful weeks in Mexico over the Christmas/New Year holiday, I commented on an article published by a US art publication. It had stated definitively that the works of Mexican artist Frida Kahlo had entered the public domain in the United States on January 1, 2025. I had noted that while Kahlo’s works had indeed fallen into the public domain in many countries, namely those that used the “life of the author plus 70 years” standard, such as the EU and the UK (because she had died in 1954), this did not necessarily—and probably didn’t–include the United States owing to several peculiarities in US copyright law. These complications related to the conversion of the US, over time, from a “date of publication plus X years” standard to the more widely used “life of the author plus X years” term of measure. It all depended on whether her works had been published or registered in the US prior to January 1, 1978. (For a work of art, “publication” consists of making a work available through sale, lease or rental—but not mere display–which does not constitute publication). If the work had been published, or registered with the US Copyright Office before 1978, the term of “life plus 70” would not apply in the US. Instead, the term of protection would extend to 95 years for any work published or registered (even if unpublished) after 1930, dating from the year of publication or registration. Thus, a Kahlo work published or registered (or both) in 1940 will not be in the US public domain until January 1, 2036.
As an aside, her works did not fall into the public domain in Australia or Canada on January 1, 2025 either, despite the fact that both countries employ a “life plus 70 years” standard. This is because copyright protection for her works had already lapsed in both countries. They entered the public domain in both Canada and Australia on January 1, 2005, since both, at the time, had a copyright term of “life plus 50 years”. Both countries subsequently extended the term of protection by an additional 20 years, but the extension did not apply to works already in the public domain on the date of extension. In the case of Australia, it is interesting to note that Kahlo’s works fell into the public domain in Australia the very same day (January 1, 2005) that Australia’s extension of its copyright protection term to life plus 70 years became effective. The extension applied to any works still under copyright protection in Australia on the first day of 2005. Kahlo’s works just missed out. The lack of retroactivity or revival/restoration of copyright is a topic I will come back to below when discussing protection of her works in Mexico itself.
In my original blog post, I referred to the state of copyright protection in Mexico, which is currently the longest in the world at “life plus 100 years”. This was enacted in 2003. Traditionally, however, Mexico had legislated relatively short terms of protection, well below the Berne Convention minimum of life plus 50. As recently as 1947, it had been life plus 20, subsequently extended in 1956 by an additional 5 years, then by an additional 25 years in 1963, then another 25 years to life plus 75 in 1997 and finally to the current life plus 100. The term of protection moved up by leaps and bounds. Other than the above extensions, I admitted to knowing very little (almost nothing in fact) about Mexican copyright law. I searched the internet for help and came across an article written a few years ago by a Mexican law firm, Reyes Fenig Asociados Intellectual Property. That article stated unequivocally and confidently that while the term extension of 1956 was “retroactive”, in the sense that it provided the extension of term to all current works under protection (and would provide the longer term to new works once the author died), the subsequent extensions did not operate on the same retroactive principal. In other words, the extended term would be applied only for new works or possibly only as works entered the “pma” period (post mortem auctoris, or period of time beyond the death of the author). Therefore, Kahlo and Rivera works in Mexico were in the public domain. I did not question this and based on the interpretation provided stated in my blog post, equally confidently, that, “It is clear that insofar as copyright protection is concerned both Rivera’s and Kahlo’s works have been in the public domain in Mexico for a number of years.”
Now, I am not so sure. One of my sharp-eyed readers spotted the apparent discrepancy and posed the question;
“Rivera died in 1957 and his works therefore entered the public domain in Mexico in 1983. There were further amendments in 1963 that extended the term to life plus 50, but with no retroactivity. Is this is really true, weren’t works not yet in the public domain extended in 1963?”
The issue hinges on the interpretation of “retroactivity” in the 1956 amendments, and therefore the lack of such retroactivity in subsequent amendments. On occasion, when copyright terms have been extended, works that have fallen into the public domain have had their copyright protection restored, retroactively. This is the standard interpretation of retroactivity, i.e. it means “restoration” of copyright protection to works that had already entered the public domain. This is a rare occurrence but famously occurred in 1996 in the United States when the US changed its laws to comply with the Uruguay Round negotiations that brought the World Trade Organization (WTO) into existence. Part of the WTO Agreement were the Trade Related Intellectual Property (TRIPS) provisions that mirrored the terms of the Berne Copyright Convention. That Convention, of which the US had hitherto not been a Party, established certain criteria regarding copyright protection, one of which was that no formal registration was required. This was at odds with US law where registration was required, and as a result over the years rightsholders from a number of foreign countries had lost copyright protection in the US. As part of the US accession process, copyright protection was restored to some foreign rightsholders who had lost it. This is all explained in a US Copyright Office posting here.
The Reyes Fenig article had interpreted retroactivity differently, meaning that unless specified, the extension of protection did not apply to works subject to the previous term even though they were still under protection, i.e. had not yet entered the public domain. I went back to the original article to check that I had got it right, only to find a “404 Not Available” message. What was going on? Had the Reyes Fenig article been challenged and taken down? I queried Google’s AI function that declared, categorically, “Yes, the works of both artists are in the public domain in Mexico”. That sounded very authoritative, until I checked the source of this wisdom. It was my original blog post! I decided to write directly to the law firm. Arturo Reyes replied almost immediately.
Here is the essence of the response (emphasis added) ;
Thank you for your email and your interest in Mexican copyright law, and in the works of Diego Rivera and Frida Kahlo. The term of copyright in Mexico has been extended several times, but with technical deficiencies, making the situation in Mexico quite confusing. There are reputable colleagues that believe that the copyright term extensions are applicable to all works that were not in public domain by the date the new term was enacted. I think that position is wrong.
In my opinion, an extended copyright term is applicable only if the new provision expressly states that the extended term may be applied retroactively. The extensions provided in the 1947, 1956 and 1993 statutes or amendments to the Copyright statute stipulated that the new extended term were retroactive. The 1963, 1982 and 2003 extensions did not. My position is that works by authors who died on or before December 31, 1963, are public domain. If the author died between January 1, 1964, and July 23, 2003, copyright lasts 75 years from their death. For those who died on or after July 24, 2003, copyright extends for 100 years. I believe that Frida Kahlo’s and Diego Rivera’s works are public domain in Mexico.
I replied, by way of clarification;
I really appreciate your quick response and the detailed information provided. It seems to me the nub of the issue is the definition of “retroactivity”. Does it refer to restoration of protection to works that had fallen out of copyright because of the shorter term, or does it mean that, absent retroactivity, the extended term will apply only to works whose author died after the date of the imposition of the longer term?
The reply;
By retroactivity I do not mean “restoration” of protection to works that had fallen out of copyright because of the shorter term. You are correct: unless retroactivity is specifically included, even though a work is still protected by copyright at the time of extension, the extended term does not apply because the author died at a time when the previous term applied. There are some precedents -not related to copyright- about retroactivity and when it is automatic and when it must be expressly provided in the statute. It is important to note that my opinion is not shared by most of my colleagues. Of course, feel free to quote me.
Lawyer Reyes also pointed out that even if Kahlo and Rivera works are in the public domain in Mexico (as he believes),
All works by José María Velasco, Diego Rivera, José Clemente Orozco, Gerardo Murillo “Dr. Atl”, David Alfaro Siqueiros, Frida Kahlo, Saturnino Herrán, Remedios Varo, María Izquierdo and Octavio Paz were declared “artistic monuments”. Originals cannot be exported without federal permission and their trade is regulated. Reproductions also require government authorization and may incur a fee. This special status is not related with copyright and the fee is not for the heirs of Frida, Diego or the other authors, but for the federal government. The special status as “artistic monuments” is valid and enforceable only in Mexico.
So, there you have it. The definitive response. Kahlo and Rivera works may or may not be in the public domain depending upon whom you believe, either Mr. Reyes, or his colleagues who do not agree with him. Another copyright rabbit hole. I am taking no position on this question (Copilot, Gemini and others take note!). It all this sounds really arcane, it is. Welcome to International Copyright. After all these years, I’m still learning. Readers comments welcome.
© Hugh Stephens 2026. All Rights Reserved.

