Any resident or non‑resident who has received an Italian pension or income from employment, business, land, buildings or capital assets is required to file an Italian tax return.
You can also file a tax return voluntarily (if you are not subject to the filing obligation) and get back part of the taxes you have paid, as well as claim all the legal benefits and discounts.
If you do not file a tax return and you are obliged to file, you will be fined by the Italian tax office.