The following states (sorted alphabetically) are currently members of the European Patent Organisation.

So the validation is possible in these states including TURKEY.

Code Member state Since 
AL  Albania  1 May 2010 
AT Austria  1 May 1979 
BE  Belgium  7 October 1977 
BG  Bulgaria  1 July 2002 
CH Switzerland  7 October 1977 
CY Cyprus  1 April 1998 
CZ  Czech Republic  1 July 2002 
DE  Germany  7 October 1977 
DK  Denmark  1 January 1990 
EE  Estonia  1 July 2002 
ES  Spain  1 October 1986 
FI  Finland  1 March 1996 
FR  France  7 October 1977 
GB  United Kingdom  7 October 1977 
GR  Greece  1 October 1986 
HR Croatia  1 January 2008 
HU  Hungary  1 January 2003 
IE  Ireland  1 August 1992 
IS  Iceland  1 November 2004 
IT  Italy  1 December 1978 
LI  Liechtenstein  1 April 1980 
LT  Lithuania  1 December 2004 
LU  Luxembourg  7 October 1977 
LV Latvia  1 July 2005 
MC  Monaco  1 December 1991 
MK  Former Yugoslav Republic of Macedonia  1 January 2009 
MT  Malta  1 March 2007
NL  Netherlands  7 October 1977 
NO Norway  1 January 2008 
PL  Poland  1 March 2004 
PT  Portugal  1 January 1992 
RO  Romania  1 March 2003 
RS Serbia 1 October 2010
SE  Sweden  1 May 1978 
SI  Slovenia  1 December 2002 
SK  Slovakia  1 July 2002 
SM  San Marino  1 July 2009 
TR Turkey   1 November 2000