The IMU reduction available for certain family loan agreements is a meaningful fiscal relief, not a total exemption. If you plan to give a home to a direct relative free of charge, it pays to know the rules that allow a cut of the base imponibile by 50%. Proper compliance with registration and residency requirements
turns a theoretical saving into a defensible reduction that stands up to municipal checks.
This article explains the essential legal reference, the operational steps to apply the reduction, the typical exclusions and technical evidence you may need to present. Keep in mind that local municipalities (Comune) can have specific procedures, so storing the right paperwork and verifying local practice reduces the risk of later recovery notices.
When the 50% reduction applies
The halving of the IMU base is set out in art. 1, comma 747, of Law 160/2019 for cases of a family comodato to a relative in the direct line. A key condition is that the property is used as the habitual residence of the borrower (comodatario), not merely available on an occasional basis. The benefit is contingent on both the factual use of the dwelling and the documentary evidence that supports that use.
Legal basis and essential documents
To claim the reduction you generally need a written and registered contract of comodato, registration with the Agenzia delle Entrate where required, and proof that the comodatario has transferred their residenza anagrafica into the house. The contract must clearly show that the property is not the owner’s principal home; if the owner also lives there as a main residence the relief will not apply. Keep receipts of registration and any official communications from the Comune.
Who can benefit and what is excluded
Only loans to relatives in the direct line are covered by the rule, and some cadastral categories are excluded. In particular, units classified as A/1, A/8 and A/9 normally do not qualify. The owner must also respect local limits: some municipalties require that the owner does not possess other residential units besides their main home. If the borrower dies, the reduction can persist in special family scenarios, for example when the surviving spouse remains with minor children, but this can vary locally.
Exceptions, technical evidence and other eligible cases
Beyond family comodato, the 50% reduction (or other abatements on the base imponibile) can apply in different situations. Properties that are legally protected for artistic or historical reasons often receive favorable treatment, provided you hold documentation of the vincolo. Likewise, buildings that are officially classified as inagible or inabitabile may attract a reduced tax base, but municipalities typically require a technical report such as a perizia asseverata to confirm the condition.
What proof matters
The mere absence of utilities is rarely enough to prove inagibility. Municipal regulations usually demand a formal appraisal or technical certificate demonstrating structural or safety problems. For protected properties, you will need the administrative act that proves the heritage constraint. In all cases, timely registration of the contract and updated anagraphic records for the comodatario are decisive.
Step-by-step checklist to apply the reduction
Follow a few practical steps before paying IMU to avoid corrections later: 1) draft and register the comodato contract with the Agenzia delle Entrate; 2) ensure the comodatario moves their residence to the property and actually lives there as their habitual residence; 3) compute the tax by halving the base imponibile and fill in the payment forms, either the F24 or the municipal IMU declaration as requested by the Comune. Keep copies of the contract, registration receipts and any municipal communications.
When in doubt, consult a professional or a certified assistance center (CAF) for a pre-payment review. A short verification of registration dates, cadastral classification and residency certificates can prevent penalties and recovery of unpaid tax later on.
Conclusion
The opportunity to reduce your IMU burden by 50% for family loans is real but conditional. Correctly combining the substantive facts (actual residence) with formal documentation (registered contract, residency records, technical reports where needed) converts entitlement into a secure, verifiable saving. Store every relevant receipt and certificate and check municipal rules in advance so that the tax benefit is both effective and defensible during any inspection.