The CIN explained for Milan short-term rentals

The CIN (Codice Identificativo Nazionale) is a unique national code that identifies a specific rental unit. Think of it as the licence plate for your apartment: one property, one code, shown on every listing and displayed at the door. Below we walk through where it came from, who needs it, how to get it, where to put it, the safety kit that goes with it, the penalties for skipping it, and how it slots in alongside the other obligations of hosting in Milan.

1. What the CIN actually is

The CIN (Codice Identificativo Nazionale) is a unique alphanumeric identifier assigned to a single accommodation unit used for tourism or short-term letting. Every apartment you let has its own CIN, tied to that specific property and to the person or company responsible for it. The point of the code is traceability: it lets guests, platforms, tax authorities and local police connect an online listing to a real, registered address and a real host.

Two features matter most in practice. First, the CIN is national, so the same code and the same rulebook apply whether the apartment is in Milan, Rome or a small town in Puglia. Second, it is public-facing: unlike a tax code that lives quietly in your files, the CIN is meant to be seen. It belongs on your Airbnb and Booking pages and on a display at or outside the property.

The CIN applies broadly to short-term tourist lets, which in Italy usually means the locazioni brevi (leases under 30 days for tourism, let by private individuals) as well as tourist accommodation structures such as case vacanze, affittacamere and bed and breakfasts. If you are advertising a Milan flat to travellers by the night or the week, you are almost certainly in scope.

2. Why the CIN was introduced

For years, Italy had a patchwork. Each region ran its own registration and issued its own regional code, formats differed, data sat in separate systems, and platforms had no single national reference to check a host against. The result was hard to police and easy to dodge.

The CIN is the fix. It was created by Decreto-legge 145/2023 (the "Decreto Anticipi"), whose article on short-term and tourist lets set up a single national scheme. The code is issued through, and recorded in, the Banca Dati delle Strutture Ricettive (BDSR), the national database of accommodation and short-let properties run by the Ministero del Turismo (the Ministry of Tourism). The database gives the state one place to see who is letting what, and the CIN is the key that ties each listing back to that record.

The stated goals were to fight tax and safety irregularities, protect guests, and give a fragmented sector a common standard. After a rollout through 2024 and a transitional window, the obligation to hold and show a CIN became fully effective across the country from the start of 2025. As of 2026 it is settled practice: no CIN, no compliant listing.

3. CIN vs CIR: how the national code replaced Lombardy's regional one

This is the point that most confuses Milan owners, because Lombardy already had a code before the CIN existed. That older code was the CIR (Codice Identificativo Regionale), a regional identification number assigned when you registered your unit on Lombardy's platform (the regional Ross1000 / Turismo5 system used for tourist data).

The CIN does not sit on top of the CIR so much as take over its public role. As of 2026, the CIN is the code you put on your listings and display at the property, and it has superseded the CIR for that purpose across Lombardy. In many cases the national database drew on existing regional records when it generated CINs, so a property that already held a CIR was mapped into the new system rather than starting from scratch.

One nuance worth keeping straight: the regional platform has not simply vanished. Lombardy still uses Ross1000 for statistical reporting of guest flows (how many guests, how many nights), which is a separate obligation from displaying an identifier. So the CIN is now the code that faces the public, while the regional system continues to run in the background for statistics. If in doubt about whether your old CIR is still needed for anything in your specific case, check with your comune.

4. Who needs a CIN

The short answer for Milan owners is: if you let a property to tourists for short stays, you need a CIN for it. More precisely, the requirement covers:

• Short tourist lets (locazioni brevi): private owners renting an apartment for stays under 30 days for tourism, whether directly or through a platform.
• Tourist accommodation structures: case vacanze, affittacamere, bed and breakfasts and similar, whether run occasionally or as a business.
• Each unit separately: the CIN is per apartment, not per host. If you let three flats, you need three CINs.

The responsibility sits with the party letting the property to guests. If you host yourself, that is you. If a management company takes the apartment on and lets it out, the registration and display duties fall to whoever is operating the let, which is a practical reason many owners hand the whole compliance job to a professional. Whether you are letting one property casually or several as a business changes other obligations (see section 9), but it does not remove the need for a CIN on each unit.

5. How you obtain a CIN

The CIN is issued through the national database, and the process is designed to be largely self-service and automatic once your record is complete.

The basic steps

• Access the Banca Dati delle Strutture Ricettive (BDSR) on the Ministero del Turismo's system, logging in with your digital identity (SPID or the CIE electronic ID card).
• Enter the property details, including its address and cadastral data (the dati catastali that identify the unit in the land registry), plus the number of rooms and beds and the type of accommodation.
• Enter the owner or host details: who is responsible for the unit and their tax code.
• Provide any prerequisites. Depending on the type of activity, the system may expect a prior regional registration or a SCIA reference where a business structure applies (see section 9).
• Receive the CIN. Once the record is validated, the code is generated and attached to that unit.

A few practical notes. Make sure the cadastral details exactly match the land registry, because mismatches are the usual cause of a stalled application. Keep a record of the CIN somewhere you can find it quickly, because you will be copying it into every new listing. And remember that obtaining the code assumes the underlying safety requirements (next section) are already met; the CIN is not a substitute for them.

6. Where the CIN must be displayed

Getting the code is only half the job. The law is specific that the CIN has to be visible, in two places.

On every listing and advertisement

The CIN must appear in every advertisement and listing for the property, wherever it is promoted. That means your Airbnb page, your Booking page, any other platform such as Vrbo, and your own website or social posts if you advertise there. If a listing exists without the code shown, it is not compliant, and the platforms themselves increasingly require the field to be filled in before a listing can go or stay live.

At or outside the property

The CIN must also be displayed at the unit, exposed outside the building where the apartment is located so that it is visible to guests arriving and to anyone inspecting. In practice this is a small plate or notice showing the code. Confirm the exact format and placement expected at the time you list, since local guidance on how prominently to show it can be updated.

7. The safety requirements attached to the CIN

The national scheme does not just register your apartment; it sets a safety baseline that goes with the CIN. For short lets in non-entrepreneurial form, the rules attached to Decreto-legge 145/2023 call for the unit to be equipped with:

• Working fire extinguishers (estintori), compliant and in date, positioned so they are accessible.
• Detectors for combustible gas (for example, where there is a gas hob or boiler).
• Carbon monoxide detectors, guarding against the odourless risk from combustion appliances.

Alongside these specific devices sits the general expectation that the property complies with ordinary building-safety standards. None of this is expensive or hard to fit, and it is exactly the sort of thing an inspection will look for, so treat it as part of getting set up rather than an afterthought. Missing safety devices are penalised separately from a missing CIN, so having the code but not the kit does not protect you.

8. What happens if you let without a CIN

The CIN regime came with real teeth, which is why it is worth doing properly from the start. As of 2026, the framework under Decreto-legge 145/2023 provides for administrative fines in situations such as these:

• Letting a unit with no CIN at all: a fine in the region of several hundred to several thousand euro, applied per unit.
• Failing to show the CIN in your advertisements or on the property: a separate fine, applied per advertisement or per breach.
• Missing the required safety devices: a further, distinct penalty.

The exact statutory ranges run into the thousands of euro, and because the breaches are counted per unit and per listing, they can stack quickly for someone operating several apartments carelessly. The specific amounts can be revised, so do not rely on a figure you read once; confirm the current numbers if you need them. The practical takeaway is simpler than the arithmetic: register the unit, display the code everywhere it is meant to appear, and fit the safety kit, and you avoid the whole category of problem.

9. How the CIN fits with your other obligations

The CIN is the anchor, but it does not stand alone. Letting a Milan apartment short-term brings a small set of parallel duties, and it helps to see how they connect.

SCIA, where it applies

If your activity crosses into running an accommodation business (for example, operating as a structured tourist activity or letting above the threshold that presumes an entrepreneurial operation), you may need to file a SCIA (Segnalazione Certificata di Inizio Attività) with the comune. As a general rule of thumb, letting more than four apartments short-term in a year is presumed to be a business, which brings a partita IVA (VAT number), a SCIA and a different tax regime. Up to four properties can usually be run as ordinary short leases. Where you fall is worth confirming professionally, and the SCIA reference can also feed into your CIN record.

Guest reporting via Alloggiati Web

Separately from the CIN, you must report each guest to the State Police. For every stay you submit your guests' identity-document details through the Alloggiati Web portal, generally within 24 hours of check-in (and on arrival for very short stays). This applies to all accommodation and is not replaced by having a CIN.

The tourist tax

Milan charges an imposta di soggiorno, a tourist tax billed per guest, per night, which you collect from guests and remit to the Comune di Milano. It applies up to a capped number of nights per stay and has some exemptions (for example, young children). The amount is set by the city and changes from time to time, so check the current rate on the Comune di Milano's website.

How the income is taxed: cedolare secca

Short lets can usually be taxed under cedolare secca, an optional flat tax that replaces ordinary income tax and certain stamp duties on the rental income. The standard rate is 21% on your first short-let property. Since the 2024 Budget Law, a 26% rate applies when you let more than one property short-term, though you may nominate one property to remain at 21%. Where a platform collects the rent it generally withholds the flat tax at source, which you then reconcile in your annual return. A commercialista can tell you whether cedolare secca or the ordinary IRPEF regime is better for your situation.

10. Keeping the CIN valid and up to date

A CIN is not a one-off form you file and forget. Because it is tied to a specific unit and a specific responsible party, changes to either can mean the record has to be updated. Keep the following in mind so the code you display stays accurate.

• Changes to the property: a significant renovation, a change in the number of rooms or beds, or a variation in the cadastral details can require you to update the record in the national database.
• Changes to the host: if the person or company responsible for letting the unit changes, for example when an owner hands the apartment to a management company, the responsible party on the record should reflect that.
• Ceasing the activity: if you stop letting the unit, the record should be updated so the database is not carrying stale entries.
• Consistency across listings: the same CIN should appear identically on every platform. A code that is right on one listing and missing or mistyped on another is still a compliance gap.

It is also worth remembering the one rule that sits entirely outside the national system: your building's own regolamento condominiale. Some Milan condominiums restrict or prohibit short-term tourist letting, and that binds you regardless of whether you hold a valid CIN. A code from the Ministry of Tourism does not override a private building rule, so check the condominium regulations before you list, not after.

A quick CIN checklist

• Confirm your regolamento condominiale (building rules) allows short tourist letting at all.
• Gather the property's cadastral data and your digital identity (SPID or CIE).
• Fit the safety devices: fire extinguishers, plus combustible-gas and carbon-monoxide detectors.
• Apply through the Banca Dati delle Strutture Ricettive and obtain the CIN.
• Add the CIN to every listing (Airbnb, Booking, your own site) and display it at the property.
• Set up the parallel duties: Alloggiati Web guest reporting, the tourist tax, and your tax treatment.
• Check whether you need a SCIA and a partita IVA if you are letting several units.