Skip to content The IMU declaration is the document through which the owner of a property informs the Municipality of any changes that affected the calculation of the municipal property tax in the previous year. In 2026, the deadline is set for 30 June. Not all property owners are required to submit it: in this guide, you will find out who must file it, how to submit it and what risks you face if you miss the deadline.
IMU declaration deadline 2026: 30 June
The 2026 IMU declaration must refer to changes that occurred during the 2025 tax year. The ordinary deadline is 30 June of the year following the one in which the change occurred. If 30 June falls on a Saturday or Sunday, the deadline is postponed to the next working day.
What is the IMU declaration?
The IMU declaration — Imposta Municipale Unica — is the mandatory communication through which the taxpayer informs the Municipality of subjective or objective changes that affect the calculation of the tax due on a property. It should not be confused with the IMU payment, which is made in two instalments in June and December: the declaration is used exclusively to report changes that the Municipality cannot independently detect from cadastral records or notarial deeds. The current model is the one approved by Ministerial Decree of 29 July 2022, consisting of a front page and Sections A and B.
When is the IMU declaration mandatory?
The IMU declaration is mandatory only if, during the previous year, a change occurred that modified the tax calculation and that the Municipality is not already able to know independently. The main situations that make it necessary are the following.
The property has obtained or lost an IMU reduction, for example because it is a historical/artistic property, unfit for use or uninhabitable. The property has been granted on free loan for use to direct-line relatives, with a 50% reduction of the taxable base. A change in the ownership share has occurred. The property is used as the main residence of the household in a Municipality different from that of the owner. Agricultural land has become building land or vice versa. The property is subject to financial leasing. A building under construction has completed renovation works.
The declaration is not mandatory if the change already results from registered deeds such as purchases, inheritances or donations, since the data is already available to the Municipality through the Italian Revenue Agency.
How to submit the IMU declaration: step by step
The first step is to download the official form, available on the website of the Ministry of Economy and Finance and on the website of your Municipality. Make sure you use the model approved by Ministerial Decree of 29 July 2022, as previous forms are no longer valid.
In the front page, enter the personal details of the declarant, the tax code, the Municipality where the property is located and the 2025 tax year. In Section A, indicate the cadastral details, cadastral income, ownership share, property type and the change that occurred, together with the relevant reference period, for each property.
You can submit the declaration through different channels: online via Entratel or Fisconline if you have the credentials, by certified email (PEC) to the address of the Municipality’s tax office, in paper format at the municipal office, or by registered letter with return receipt. Whatever channel you choose, keep the submission receipt for at least five years.
IMU declaration for non-resident and foreign property owners
If you own a property in Italy but are not resident in the country — whether you are an Italian citizen registered with AIRE or a foreigner owning property in Italy — managing the IMU declaration may involve additional complexities. You must verify whether your property benefits from the IMU exemption for AIRE introduced in 2023, how any loan for use or lease affects the tax, and whether you are correctly applying the rates approved by your Municipality for the 2025 tax year.
Are you a non-resident property owner in Italy? IMU management for non-residents and foreigners requires a specific assessment. Our tax consultants help you verify whether you are required to submit the declaration, correctly calculate the tax and avoid penalties. Book an online tax consultation.
Penalties for omitted or late IMU declaration
| Type of violation | Basic penalty | With voluntary correction |
|---|---|---|
| Omitted declaration | From 100% to 200% of the tax | Reduced to 1/8 |
| Incorrect declaration | From 50% to 100% of the tax | Reduced to 1/8 |
| Late declaration within 90 days | 10% (minimum €50) | Voluntary correction |
The minimum penalty for omitted declaration is €50.
Voluntary correction for late IMU declaration
If you forgot to submit the IMU declaration within the deadline, you can regularise the situation through voluntary correction, paying the reduced penalty together with the tax due and accrued interest. The applicable reduction depends on how much time has passed since the deadline: within 30 days the penalty is reduced to 1/10, within 90 days to 1/9, within one year to 1/8, after one year to 1/7 and after two years to 1/6. Payment is made through the F24 form, using the specific tax code communicated by the Municipality.
FAQ
When must the 2026 IMU declaration be submitted?
By 30 June 2026, for changes that occurred during the 2025 tax year.
Does the IMU declaration have to be submitted every year?
No. It must be submitted only in the year following the one in which a relevant change occurred. If there are no changes, there is no obligation.
How can the IMU declaration be submitted online?
Through the Italian Revenue Agency’s electronic channels (Entratel or Fisconline) or by certified email (PEC) to the tax office of the Municipality where the property is located.
What happens if I do not submit the IMU declaration by 30 June?
You risk a penalty from 100% to 200% of the undeclared tax, with a minimum of €50. You can reduce it through voluntary correction if you act before receiving an assessment notice.
Am I exempt from IMU if I am registered with AIRE?
Since 2023, Italians resident abroad and registered with AIRE may benefit from the IMU exemption on one property owned in Italy by title of ownership or usufruct, provided that it is not leased or granted on loan for use.
Do you need support with your IMU declaration?
Whether you are resident in Italy or abroad, whether you own a single apartment or a real estate portfolio, Arletti Partners’ consultants support you with the completion, submission and optimisation of your IMU tax position. Book a tax consultation with a guaranteed response within 48 hours.