Every country in the euro zone can issue once a year a 2 euro commemorative coin. These coins have the same features and the same properties as usual 2 euro coins and their common side is identical. They are different as regards their commemorative design which illustrates their national side. Only 2 euro coins can have commemorative issues. Commemorative coins have legal tender within the whole euro zone. That means they can be used –and must be accepted- as any other euro coin.

Most of these coins celebrate an historical event or draw attention to a present issue that refers to history facts. The first commemorative coin was issued by Greece in 2004 to commemorate the Olympic Games in Athens.

The basis for the commemorative coins is derived from a decision of the European Council, which allowed changing the national obverse sides of euro coins from 1st January 2004 onwards. OJ C247/03 However, a number of recommendations and restrictions still apply.

Two restrictions concern the design. Euro coins must still have a common reverse side, so only the national obverse sides may be changed. Also, the standard national obverse sides per se should not be changed before 2008 at the earliest, unless the head of state depicted on some of the coins changes before then. (This clause already came into effect for Monaco and the Vatican City, whose heads of state—Rainier III and Pope John Paul II respectively—died in 2005 and whose national obverse sides were changed for 2006.)

Further regulations restrict the frequency and number of commemorative coin issues. Each member state shall only issue one commemorative coin per year, and it shall only be denominated as a €2 coin. The total number of such coins put into circulation per year should not surpass the higher of the following two numbers:

0.1 % of the total number of €2 coins put into circulation by all members of the eurozone. This limit can exceptionally be increased to up to 2.0 per cent if the coin commemorates a very important and noteworthy event; in this case, the member state issuing this higher number of coins should refrain from putting any commemorative coins into circulation for the following four years.
5.0 % of the total number of €2 coins put into circulation by the member state issuing the €2 commemorative coin.

Another decision added two more guidelines regarding the design of the coins. The state issuing a coin should in some way clearly be identified on the obverse side, either by stating the full name or a clearly identifiable abbreviation of it; and neither name nor the denomination of the coin should be repeated on the obverse, as it is already featured on the common reverse side. OJ L186/01

These restrictions do not apply retroactively; only new designs—the national obverse sides for regular issues of states newly joining the euro or of eurozone states which change their design, and €2 commemorative coins issued from 2006 onwards—are subject to them. However, the five countries whose designs violated the first update to the rules (Austria, Belgium, Finland, Germany and Greece) initially were assumed to have to change their design in the near future, which Finland did for 2007 and Belgium for 2008.

Another decision changed the rules again: OJ L9/09

The twelve stars of the European Union surrounding the coin designs need to surround all of the coin design elements, including year marks, mint marks and the name of the country. The stars have to appear in the same way as they are aligned on the flag of the European Union. (These recommendations are not currently fulfilled by the Dutch, Italian and Luxembourgish coins.)

The design of euro coins may not be changed except for two specific circumstances:

• If a coin design is in violation of the recommendations, it may be updated to bring it into line with them. (This applies to Austria, Germany, Greece, Italy, Luxembourg and the Netherlands.)
• If a coin design depicts a head of state, it may be updated:
  1. every fifteen years to bring it into line with the head of state's current appearance;
  2. if the head of state abdicates or dies. However, temporary heads of state may not be used as a reason for changing the design; instead a €2 commemorative coin (potentially a second €2 commemorative coin) will be allowed to be issued.

The edge lettering of commemorative coins has to be the same as the one on the regular coins.

(These provisions forced Belgium to change its design back to show the original portrait of its monarch, because the 2008 update to follow the recommendations also updated the portrait, which was against the rules. The Belgian coins from 2009 onwards show the original royal portrait of 1999, but otherwise keep the new 2008 coin design as far as the country identification and year mark are concerned. These provisions additionally prohibit further sede vacante sets of coins by the Vatican City, allowing only commemorative coins for such occasions.) Slovakia, Slovenia and Spain were the states which were in breach of these new guidelines. Spain updated their design from 2010 onwards to meet the new rules, leaving Austria, Germany, Greece, Italy, Luxembourg, the Netherlands, Slovenia and Slovakia in breach of them. The recommendation will be reviewed in 2015.