Printer: Various Countries, see below
Signature 1:  Dr. Willem F. Duisenberg
Signature 2:  Jean-Claude Trichet
Signature 3: Mario Draghi
SIZE: See table below

The first character of the serial number is a letter which uniquely identifies the country that issues the note. The remaining 13 characters are numbers which, when added up and the digits of the resulting sum then added together again until a single digit remains, give a checksum also particular to that country. Because of the arithmetic of the check-sum, consecutively-issued banknotes are not numbered sequentially, but rather, "consecutive" banknotes are 9 digits apart.

The W, K and J codes have been reserved for the EU member states currently not participating in the euro, while the R, F and G prefixes are reserved for states within the Eurozone that, at present, do not issue euro banknotes.

• The positions of Denmark and Greece have been swapped in the list of letters starting the serial numbers, presumably because Υ (upsilon) is a letter of the Greek alphabet, while W is not.

• Ireland's first official language is Irish; however, in the above chart it is clear the order was based on the English Ireland rather than the Irish which is Éire. Note that if the Irish spelling were used, Ireland would be represented by the letter V, which is not used in the Irish language except in some borrowed words. By using Ireland, the letter T is acquired, which is used in the Irish language.

• In the case of Finland, which has two official languages that are also official EU languages (Finnish and Swedish), the order was based on the Finnish Suomi instead of the Swedish Finland, presumably because Finnish is the majority language in the country.

• Belgium has three official languages, all of which are official EU languages. Luxembourg also has three official languages, with two being official EU languages. However, in these cases, the countries' positions in the list would be the same no matter which language was used.

The notes of Luxembourg currently use the prefix belonging to the country where they were printed.

Although the Slovenian letter had been reserved since the eurozone enlargement in January 2007, the country initially used previously issued banknotes issued from other member states. The first banknotes bearing the "H" letter, produced in France specifically on behalf of Slovenia, were witnessed no sooner than April 2008^[11].

Cyprus and Malta will print first own 20€ notes in 2009.^[12]

It seems from that further country codes are assigned in reverse order from the last assigned code "J" for the UK, according to the time a country joins the Eurozone. When two or more countries join at the same time, the same rule is followed as with the initial assignments of country codes, i.e. the country codes are alphabetised according to the countries' names in the official language of each country, but reversed. "H" was assigned to Slovenia which joined the Eurozone in 2007 following "J" which was the last letter assigned so far, to the UK. Then when Cyprus and Malta joined in 2008, "G" was assigned to Cyprus (Κύπρος [Kypros] in Greek, Kıbrıs in Turkish, the island's two official languages both starting with the letter K), "F" was assigned to Malta and "E" was assigned for last member Slovakia.

It has been suggested^{[citation needed]} that, should the prefixes change to two characters, the code should be the state's ISO 3166-1 alpha-2 code (e.g., EE for Estonia, DE for Germany).

The initial design of the euro with the 2002 signature of Wim Duisenberg, has been issued in each of the 7 denominations by each of the NCBs of Finland, Portugal, Austria, the Netherlands, Italy, Ireland, France, Spain, Germany, Greece and Belgium, with the exception of the €200 and €500 banknotes from Portugal and the €200 banknote from Ireland. Thus, there are 74 country/denomination varieties of the banknotes with the Duisenberg signature.

These printing codes have an initial letter, followed by 3 digits, followed by a single letter, and ending in a digit, for example, "G013B6."

The initial letter identifies the printing facility, as described below. "G" for example would be Enschede & Sons, a printer in the Netherlands. The 3 digits identify sequential printing plates. "013," for example, would be the 13th printing plate created by the printer. The fifth character, a letter and sixth character, a number, represent the row and column, respectively, of the particular banknote on the particular plate. So "B" would be the second row and "6" would indicate the sixth column.^[14]

Banknotes are printed in sheets, with different printers using different sheet sizes, and sheets of higher denominations, which are larger in size, would have fewer banknotes printed per sheet. For example, the two German printers print €5 banknotes in sheets of 60 (10 rows, designated "A" through "J" and 6 columns), the sheets for €10 banknotes have 54 banknotes (9 rows, 6 columns), and for €20 banknotes have 45 banknotes (9 rows, 5 columns) ^[15]