New countries are slowly making surface regarding some 2024 and 2025 omnibus series:

Stamps from Mauritania relative to the UPU 150th anniversary (apparently 4 stamps, only one seen so far – T20241009), and the 80th anniversary of the Arab League (4 stamps – T20250322) became available. Dates of issue are unknown. Only bad quality images are available so far. Note that the currency used on these Mauritanian stamps is wrongly expressed in “RMU” instead of the correct “MRU”, making these issues questionable. Additional information is welcome. At the same time Saudi Arabia issued also two stamps, one related to this same Arab League 80th anniversary (T20250322), but issued one year later, on March 22, 2026, and the other related to the Arab Postal Day (T20250803) and issued on March 14, 2026. Thanks to Kenneth Sequeira, Dubai and Ali Ahmed Med Achour, Algeria, for this information. Source of the Mauritania stamps’ illustrations is Busch Collectibles.

During the year 2025, we also forgot to mention the joint issue between the three United Nations offices of Geneva, New York and Vienna related to the 80th anniversary of the United Nations. As usual, when only these three offices are involved, we cannot consider those stamps as joint, but the catalogue mentions (in italics and gray color) all issues of these offices when design and illustrations are identical. So, we will complete the catalogue with this information (provided by Jaap Sarelse, the Netherlands), but file it under N20251024. Issue date was October 24, 2025 and mixed first day covers were also made available.

From Adam Paish (UK): To celebrate the centenary of the birth of the late Queen Elizabeth II, similar commemorative mini-sheets will be issued, each containing four different stamps, by the postal administrations of Ascension Island, Falkland Islands, South Georgia and the South Sandwich Islands and Tristan da Cunha. The stamps depict photographic images by the British society photographer Marcus Adams (1875-1959) and are scheduled for release on April 21, 2026. The Bahamas postal administration also plans to release a set of four stamps in the same photographic style on April 16, 2026, but these may not be in an identical sheet format. This is not a true joint stamp issue, but definitely worthy of mention and will be described without details (omnibus series [PO]) in the catalogue. 

New Zealand, Gibraltar and the United Kingdom have also released or will be releasing stamps to mark the anniversary, and no doubt other countries will follow.  

Among the true joint issues, two were confirmed, but are involving Uruguay, another country from where it is difficult to obtain information. On March 26, 2026, Uruguay issued stamps jointly with Mexico (125 years diplomatic relations) and on March 30, 2026 with Indonesia (handicrafts) (Information provided by Kenneth Sequeira, Dubai and Enzo Cafaro, Italy). The Indonesia stamp designs have been available for a couple of months and the picture of the Uruguayan stamps related to Mexico became available recently, but all other information in particular from Mexico, is still missing. The catalogue pages will be updated as soon as information is more complete (it may take another two weeks).