Trenitalia has just modified the rule for the 50% child's fare, extending it to children up to the age of 15 years, 0 days (from 12 years, 0 days).

New rule: Children up to 15 years, 0 days qualify for 50% of the "BASE" fare on Trenitalia RESERVED trains.

THE AGE EXTENSION TO 15 YEARS, 0 DAYS DOES NOT APPLY TO THE UNRESERVED "regionale" trains, which (at least for the moment) retain the prior rule of 12 years, 0 days.

NOTE: Sometimes, the "ECONOMY" and "SUPER ECONOMY" fares will be LOWER than the Child's fare, so you must always check all offers. However, these other promotional fares have restrictions which the "BASE" fare does not have.

NOTE: Children up to the age of 4 years, 0 days CONTINUE to travel FREE on ALL Trenitalia trains, WITHOUT a ticket and WITHOUT a guaranteed seat.

Here is the new rule, as reported in a Trenitalia press release:

I bambini diventano grandi

Riduzioni fino al 50% sul prezzo del biglietto per i ragazzi che viaggiano sulle Frecce, e gli altri treni a media e lunga percorrenza, fino al compimento del 15° anno d’età.

The new rule takes effect on Sunday, December 9, 2012.