In English, the plural of one "euro" is two or more "euros". This has been clearly established in past versions of the English Style Guide of the European Commission Translation Service, as noted below.

A February 2009 HTML version, replacing the previous July 2005 PDF revision, which itself replaced the November 2002 PDF version, can be found via the EU Inter-Institutional Style Guide (specifically for treatment of the euro in texts see section 7.3.3., currently dated 05 February 2009 but under revision for republication "by the end of 2009."

Examples of the use of 'euros' can be found in Section 3 (Numbers: 3.2 and 3.3) and usage guidelines in Section 20 Currencies, including the following extract:

Guidelines on the use of the euro, issued via the Secretariat-General, state that the plurals of both 'euro' and 'cent' are to be written without 's' in English. Do this [only] when amending or referring to legal texts that themselves observe this rule. However, in all other texts, especially documents intended for the general public, use the natural plurals `euros' and `cents'.

The November 2002 edition of the Style Guide, no longer on-line, was even more clear on this point, as noted from the following extracts from Section 12 — Currencies:

12.09

• In English, the singular form is euro and the plural form is euros.

12.11

Where a sum is written in words, use the forms:

• a sum of seven million U.S. dollars; a sum of two million euros.

12.12

In tables and documents where monetary amounts are often mentioned, make maximum use of the ISO 4217 [PDF] abbreviation "EUR" (before the amount) or the "€" symbol (closed up to the figure), e.g. EUR 147,000.00 or €147,000.00