In order not to be subject to VAT, the free supply must be included in the original supply contract

The Italian tax authorities’ ruling reply no. 584 of December 14, 2020 clarified that an agreement that does not have the purpose of redetermining the original price of the supply does not constitute an allowance pursuant to Article 15(1)(2) of Presidential Decree No. 633/1972.

Source PwC Italy blog