Updated on January 7, 2006

The new classification system that has been used in the new Catalogue of Joint Issues 2006 is now available as a pdf file

The text provided below is a non-illustrated summary of this classification system

Joint issue: Definition

A Joint Issue can be declared only when two or more independent postal administrations sign an agreement to create new postage stamps or items for postal use with a common interest and issue them within a pre-defined timeframe

Details:

· two or more: there is no limitation in the number of countries involved. A series becomes an "omnibus series" if the same printing house is producing all stamps for all countries for economic reason (abusive issues" and not when it is linked to the number of countries or the fact that these countries are administratively dependent.
· independent: Only postally independent countries can be involved. This excludes colonies and territories if the stamps are issued only together with the mother country. Territorial or Colonial issues become a specific sub-class. On the contrary if another independent country is involved, the whole territorial or colonial issues become part of the joint issue
· postal administrations: not to be confused with printing house. Therefore omnibus series produced at a same printing site (House of Questa, Crown's agent, …) for which only the name of the country is modified will not be considered as joint issues. On top of that, the country (postal administration) must be recognized by the UPU at the time of release of the stamps.
· signature: The issue has to be approved as joint by both (or more) postal administrations during at least the preparation or design phase. Therefore issues discussed at the level of the UPu or any type of collectivity or organization (SAARC, Norden, OPEC, Arab League, CEPT, …) must be considered as joint as well.
· agreement: either an official statement by one of the postal administration must be published, or mixed official covers are produced by the administrations (and not a dealer or privately). Therefore the use of first day covers completed with stamps from the second country after the issue of the stamps of the first country (post-cancellation) cannot be considered as joint issue. For most of the older issues it is difficult to provide this proof. Therefore, in main cases a special sub-class was proposed (waiting list).
· new: reprint of older issues are not accepted, nor overprinted stamps can be considered as joint issues
· postage stamps or items: stamps, souvenir sheets and booklets are the most common items used in joint issues, but postal stationery such as cards, letters, aerogrammes can be part of joint issues as well. Even revenue stamps and stamp labels could be accepted
· postal use: any item produced within this frame must be accepted as payment for mailing. Therefore if only documents without postal value are produced, the issue cannot be considered as joint. Of course complementary material without postal value (e.g. black prints, assays, …) to a true joint issue will be described
· common interest: all stamps have to be commemorative stamps (topical or anniversary) and preferably related to an event that is common to both countries
· defined timeframe: the time between the two dates of issues must be as short as possible. This time will define sub-classes of joint issues (twin, parallel or concerted). However, it can happen that for technical or political reason the difference between two issues can be as big as several months. These issues will be accepted as well. Aborted joint issues will be considered also each time the information is available.

Two characters are used to describe a joint issue subtype. The first letter stands for the sub-group: U: Unique, S: Se-tenant joint (replacing formerly Siamese), T: Twin, C: Concerted, P: Parallel. The first part groups all "true" joint issues, including those that did fail. Subclasses are detailed by using a figure. In the second part are gathered all joint issues that have to be considered as "doubtful" or "not true joint issues". They use the same lettering system (T, C and P) followed by another letter explaining the sub-class: O: Omnibus, D: Territorial (or Colonial) - Dependencies, A: Accidental.

Part 1: True joint issues sub-classes

Part 1 collects all series for which it is obvious that there was at least a will to produce joint issues together, either based on the design or the date of issue. The difficulty to add new series to these lists starts when some of the countries are politically linked to each other. If more than two countries are involved in a series, two countries are sufficient to define the group to which this series will belong. Therefore, when only two countries issue identical stamps at the same date beside several other countries issuing stamps at different dates or with different designs, these two countries will define the priority in the classification system.

1.1. Unique and Se-tenant joint Issues

Unique issue
U1 One single stamp (or postal item) issued for two countries Names of both countries present on the stamp - Liechtenstein - Switzerland (1995)
U2 One single stamp (or postal item) issued for two countries No name of country on the stamp, but used in several countries - Austria - Hungary (1 June 1867)
UT Territorial Unique Issue One single stamp (or postal item) issued for different territories or colonies. Unique issue involving dependent countries (extremely rare and should normally belong to Part II - no sufficient examples to create a specific sub-group in Part II) - No example known up to now

Se-tenant joint issue
S1 Two stamps from different countries, issued se-tenant or part of the same souvenir sheet Stamps with the same design that can be separated to be used in their respective country - Italy and San Marino (8 October 1994)
S2 Two stamps from different countries, issued se-tenant or part of the same souvenir sheet Stamps with a different designAlthough se-tenant, stamps can be used for postage only in their originating countries - Yugoslavia and Romania (1965)
ST Territorial Se-tenant joint issue Two stamps from different territories (or colonies), issued se-tenant or part of the same souvenir sheet Se-tenant joint issue involving dependent countries (extremely rare and should normally belong to Part II - no sufficient examples to create a specific sub-group in Part II) - St Helena, Ascension, Tristan da Cunha (4 May 1976)- Tonga and Niuafo'ou (July 1998)

1.2. Stamps with the same design

Twin issue
T1 Identical stamps issued on the same day. Most common case, basis of the Joint Issues collection Difference between dates of issue can be up to one week.
In some very specific cases, territorial issues (normally classified as TD) can be found in this class, e.g. when only one territory is linked with a specific topic to the father country: Portugal - Macao (9 June 1997)
T2 Identical stamps issued on the same day (several countries involved) When more than two countries are involved but not all of them are issued on the same day, the most common day will be kept - Europa CEPT stamps with the same design and with less than half of the countries being issued at the same date
T3 Similar stamps issued on the same day The design is the same, but one item or part of the design is adapted to the specific country. If there are only differences due to size, printing processes, paper quality, colors or perforations, these stamps will still be considered as T1 - Germany - Japan (1996)
T4 Identical souvenir sheets issued on the same day with different stamp cuts. The basic design of the souvenir sheet is the same for both countries, but stamps including printing of the country name and denomination are taken for each country at different positions in the souvenir sheet. Once cut out from the souvenir sheets, stamps should be classified as P1. Jersey Guernesey (1 October 1994)
TX Identical stamps issued on the same day … but without real proof that the stamps were really issued jointly. They could be T1 stamps. Classified as TX until more information is available - Pilgrimage to La Mecca (1979) - Egypt (7 November) - Iraq (9 November) - Kuwait (9 November) - Oman (1 November) - Saudi Arabia (6 November)


Concerted issue
C1 Identical stamps issued at different dates Difference between dates of issues superior to one week. Postal administrations must claim the stamp being issued jointly and explain the difference
C2 Identical stamps issued at different dates This sub-class contains also stamps that were initially not announced as joint, but for which one country offered the design to another country for implementation in their philatelic program
These stamps will be sub classified as C2 only if known - Spain and Chile or Bolivia
CX Identical stamps issued at different dates Same as C1 but no proof with mixed cover. Joint issue for which there is still a doubt will in this class as long as they cannot be categorized as C1, C2, CD, CO or CA

1.3. Official Joint Issues

Parallel issue
P1 Different stamp design but issued at the same date Difference between dates of issue can be up to one week. Postal administrations must claim the stamp being issued jointly and explain the difference of design or official (not private) mixed cover exists
P2 Different stamp design but issued at the same date. Same as above but no proof with mixed cover. Joint issue for which there is still a doubt will remain in this class as long they cannot be categorized as P1 or PA


Delayed (Retarded) joint issue
R1 Different design and different initial date but postal agreement Production of one stamp by one country and existence of official mixed covers by using one previously issued stamp from the other country with authorizations from both postal administrations
France and Switzerland (Leman Lake, 19 February 1985)
R2 Delayed - double anniversary issue.Different designs and different initial dates but postal agreement. Delay officially acknowledged and due to the time gap between two linked events, that happened consecutively in both countries. Departure from Pitcairn (3 May 1981) and arrival at Norfolk (5 June 1981)

1.4. Uncompleted Joint Issues

Non issued or Aborted
N Uncompleted issue Counterpart stamp missing or stamps that were finally not issued (however designer and printing samples exist), or printed later at another occasion, although the agreement between the postal administration was published
Argentina and Brazil

Part 2: Common issues sub-classes

Colonies, territories, omnibus series, joint issues with too large time between their issue date and false joint issues are collected in this second part. For purists, all these stamps should not be considered as joint issues.

2.1. Territorial and colonial (Dependencies) Issues

As the definition of a colony differs from one country to another, there will be no splitting between territorial and colonial issues. The term territorial includes all countries that are "postally" dependent from another, whatever they are called colonies, territories, oversea department, dominions, etc. Once such a territory gains its complete postal independence and produces its own stamps all different from the "politically" parent country, it will be considered as a country per se. If only a sub-group of the colonies or territories is involved (without participation of the father country) and if the topic is related to a local event, then these stamps will be considered as normal Twin (T1/T2/T3) or Joint (C1/C2 or P1/P2) series.

TD Territorial (or colonial) twin issue. Identical stamps issued by postally dependent territories (or colonies) at the same date List of administrations considered as territories is given elsewhere. However stamps issued jointly with another country than the father country must be considered in Part I, T1/T2 - Dutch Antilles - Netherlands - Surinam (29 June 1971).Overprinted territorial twin issues with different colors will be classified under this heading as well.
CD Territorial (or colonial) concerted issue. Identical stamps issued by postally dependent territories (or colonies) at different dates List of administrations considered as territories is given elsewhere. However stamps issued jointly with another country than the father country must be considered in Part I, C1/C2
PD Territorial (or colonial) parallel issue. Different stamps issued by postally dependent territories (or colonies) at the same date List of administrations considered as territories is given elsewhere. However stamps issued jointly with another country than the father country must be considered in Part I, P1/P2

2.2. Omnibus Series (**)

Omnibus Series include all large series of stamps printed at a same place by the same printing house for countries that are not linked politically. British Territories issues from the 40's and 50's have got the generic catalogue name of "omnibus series", due to the number of countries involved, but they cannot be considered under this heading, as at that time, these countries were directly governed by Great Britain. Therefore these series will be classified as Colonial/Territorial under TD, CD or PD and the following issues become TO, CO or PO series as soon as independent countries participate to the issue. Actually the modification of classification is linked to the date at which the country gained its independence. In case of doubt, the double classification may be used (e.g. TO/TD) as some collectors may also want to consider the classical omnibus series under the heading TO and not TD.
Usually omnibus series involve at least five countries and the total number can go higher than 20. However some of the series that are produced on the basis of the same design by the same printing house can be limited to as low as two countries. If it is obvious that there is no postal or political link between these countries, these stamps will still be classified under this heading "omnibus" and the definition will be precised as "Same printing house series".
Series initiated by an association of countries (e.g. Arab League, Europa/CEPT, OPEC, SAARC, Norden, …) cannot be considered as omnibus series.

Omnibus series

SO Se-tenant joint omnibus series. Stamps from different countries se-tenant; Design is similar, but stamps can be different. Of course common printing house. Produced as copies of each other in order to reduce printing costs. Usually the number of involved countries is much higher than five.
TO Twin omnibus (or same printing house) series. Same or common design and same date of issue In all cases, common printing house Produced as copies of each other in order to reduce printing costs. Usually the number of involved countries is much higher than five. Example: 1981 (22 July), involving 39 countries. The criteria for switching from Territorial TD to Omnibus TO is the presence of independent countries, in this case Gambia or Sierra Leone.
CO Concerted omnibus (or same printing house) series. Similar design, but different date of issue In all cases, common printing house. Produced as copies of each other in order to reduce printing costs. Usually the number of involved countries is higher than five. Example: Stamps "United we stand" commemorating the 11 September attack by several countries at different dates during 2002, showing each the local flag.
PO Parallel omnibus (or same printing house) series. Same date of issue but different design In all cases, common printing house. Actually design remains similar (frame) and stamps are produced as copies of each other in order to reduce printing costs. Usually the number of involved countries is higher than five. Example 1986 (23 July) Prince Andrews marriage with Sarah Ferguson: design for all stamps is similar but the central photograph is different for each one

2.3. Accidental Joint Issues

Accidental Twin Issue
TA Same design and same date of issue … but obviously no. Twin Issue, as they are issued without agreement between postal administrations. Usually these stamps are issued at an anniversary date and are based on the same painting or picture
Ex.: On the 150th birthday (1972) of Louis Pasteur several countries issued a stamp in honour of the scientist and used the same classical painting.

Accidental Concerted Issue
CA Same design but different date of issue and no link between countries. Obviously stamps being produced based on the same design (e.g. portrait, logo, painting, …). Some issues can have several years of difference. Ex: France and Venezuela used exactly the same logo for their anti-smoking campaign. Stamps are almost identical. The first one was issued on 5 April 1980, the second one on 27 May 1993.

Accidental Parallel Issue
PA Same topic and same date of issue but different design Obviously not a joint issue as, for example, those stamps produced at an anniversary date, but without agreement between postal administrations - Enrico Fermi, USA - Italy (2002)

Borrowed design
BD Same design as an already existing joint issue, but not being part of this issue Includes also shared, rented, borrowed or even stolen designs - Bulgaria, parallel to the Norden issues. Will be described with the original basis design

2.4. Non-Accepted Joint Issues (non exhaustive lists)

Overprinted Issue
OP Common date, but only overprinted stamps The issues that will be reported are exceptions. Overprinted stamps are normally excluded from the scope

Non-commemorative issues
NC Common date and common design but definitive stamps Definitive stamps are excluded from the scope - Usually first colonial stamps

Non UPU recognized countries
NR Stamps issued by countries not recognized by the UPU Joint issues are limited to countries that have a political and postal worldwide accepted existence at the time of issue of the stamp - Abkhazia and Ossetia (1996)

Common issue
CM Same topic but different design and different date of issue Except as examples, those will not be reported in the catalogue

False joint issue
FJ Only the topic is common Any stamp pair that does not fit with one of the above definitions - Non exhaustive list of common design or topic stamps issued the same year, but definitely not as joint issue

2.5. Joint Cancellations (non exhaustive list)

Common cancellation
JC Creation of a specific cancellation Agreement between postal administrations to cancel jointly stamps with similar topics. Non-exhaustive list. The issues that will be reported are exceptions.