1. presence of subtraction - the case more common is the presence of subtraction that nullify the two taxes. But if in case of tasi is a jungle of discounts that varies to the choice of common and that generally depends from the cadastral income of the house, earnings of the owner, the isee of the family and the age of the occupant

2. tasi exemption - is the case in which the common has choiced to not apply the tasi on one or more categories of real estate. As regards the first home, a mayor on ten has decided to not charge the tasi. while on the other real estate, the tasi doesn't charge in 50% of cases. This isn't  automatically in a reduced tax burden for the contributor (because the imu could be more expensive), but sure calculate the amount to pay is less difficult

3. minimum threshold of tasi and imu deposit - the government rules have established a minimun threshold equal to € 12, but the common had the possibility to decide a different threshold ( two state capital on three, for example, have reduces the threshold to 10,5 or 2 euro). The minimum threshold is specified in the imu and tasi regulations and are expected different threshold for the two tributes. the amount also refers to the payment, who has not paid the deposit for 7 euros, for example, the balance will have to pay 14 euros

4. zero cadastral income - the properties that are in category f/2 of "collabenti" (ruined properties, without roof or with structural damages) not pay imu or tasi because have the cadastral income zero. in some cases the common could tax the building area. if the property is considered unusable, the taxable amount of imu and tasi is reduced to 50%

5. imu farmlands - the dm published on 6 of december has redefined the perimeter of farmlands exempt from imu, after various protests has decided the deferment of payment for who isn't exempt to the 26 of genuary