Since 16/08/1992, when Law n. 91/1992 was ruled out, the voluntary acquisition of another citizenship no longer results in the automatic loss of Italian citizenship.
1) Italian citizens who voluntarily acquired another citizenship before 16/08/1992, automatically lost their Italian citizenship (art. 8 of Law n. 555/1912).
However, they will be able to re-acquire their Italian citizenship, without losing the other citizenship, as per provisions of art. 13, Law n. 91/1992.
At the same time, Italian women who married a British citizen after 01/01/1949 (British Nationality Act 1948) voluntarily acquired British citizenship and lost their Italian citizenship.
Click here for more information on the re-acquisition of citizenship by residence in Italy.
(Information on re-acquisition of Italian citizenship, for those who lost it due to the acquisition of another citizenship before 16/08/1992 and for women married to a British citizen after 01/01/1949 )
2) Italian women married to British citizens before 01/01/1948 lost their Italian citizenship whilst not-voluntarily acquiring British citizenship. These women can re-acquire Italian citizenship ex nunc through a formal declaration of re-acquisition to be submitted to this Citizenship Office (Law n. 151/1975).
(Documents to submit for re-acquisition of Italian citizenship ex nunc, for Italian women who lost Italian nationality by marriage with a British citizen before 01/01/1948 )