On June 27, 2022, Mexico issued a stamp celebrating the centenary of the building of the Mexican embassy in Rome, Italy. Such a stamp was not in the program of the Italian philatelic program, but shortly after the release of the Mexican stamp we learned (Source: Fabio Bonacina and Enzo Cafaro, Italy) that the Italian postal administration intended to produce also a stamp related to this topic by end of July 2022. We had to wait very closely to the release of the Italian stamp to discover its design which eventually appeared to be the same. Italy issued its stamp on July 28, 2022.

None of the postal administrations claim a joint character to these stamps. It looks that the Italian administration had to react quickly after they learned about the issuance of the Mexican stamp, probably only during the spring of 2022. Nevertheless, it became obvious that we had to consider this issue as joint for several reasons:

• The building and the topic are unique to Mexico in Italy
• The Mexican ambassador participated to this issue confirmed by a text written by him in the presentation package of the Italian stamp. Indirectly, Mexico was involved in the Italian stamp creation discussion
• The fact that there was an agreement on the image is also a confirmation of the collaboration. The situation would have been more questionable if the designs were different or if one stamp would only give a simple text
• Slight differences such as appearance of Mexican flag in the Italian stamp are minor modifications that can be considered as the degree of freedom left to the two designers, but both had to work on the same basic picture
• However,there was a kind of hiccup in the decision to collaborate and absence of agreement on date of issue. The official anniversary is July 2, 2022, so none of the two first day dates (June 27 and July 28). This could be the consequence of last minute decision to collaborate

In summary: this issue will be considered as joint, with the sub type concerted [C20220627] (same design but different dates of issue) and the lack of communication about the joint character is mainly due to the short time left to the two postal administrations to define a common date. Apparently, the Italian postal administration considers a true joint issue only if both stamps are released on the same day and if mixed joint FDCs can be created on this day. These mixed documents will probably exist in the near future, but of private origin.