Signing a lease online in Trieste: which signatures are valid

Yes, a lease can be signed online, but not with just any signature. Law 431/1998 requires written form for a valid lease and, if the lease is an electronic document, Italy's digital administration code requires, on pain of nullity, at least an advanced electronic signature, or else a qualified or a digital one, or the signing process meeting AgID requirements set out in article 20. A scanned signature or an "OK" by email is not enough.

Why does the signature matter so much?

Because for the lease of a home written form is a condition of validity: valid leases require written form (law 431/1998, article 1). The civil code, in article 1350, lists the acts that must be made in writing on pain of nullity, and at number 13 adds the other acts specifically indicated by law.

The digital administration code (legislative decree 82/2005, article 21, paragraph 2-bis) links the two. Acts under number 13 drawn up as an electronic document must be signed, on pain of nullity, with an advanced, qualified or digital electronic signature, or formed through the process in article 20, which identifies the author under the requirements of AgID, the national digital agency. For numbers 1 to 12, including leases over nine years (number 8), a qualified or digital signature is needed, unless the signature is authenticated.

Without these signatures, article 20 generally leaves it to the court to decide whether the electronic document has written form; for a contract the law wants in writing, article 21 leaves no room.

The signatures, from strongest to weakest

• an advanced signature created with a qualified device and based on a qualified certificate; the digital one uses a private and a public key

  Signature: Digital or qualified electronic

  For the lease of a home: valid; mandatory over nine years

• uniquely linked to the signer, identifies them, is under their sole control and reveals any later change to the signed data

  Signature: Advanced electronic

  For the lease of a home: valid up to nine years

• data in electronic form used to sign, without the requirements of the advanced one

  Signature: Simple electronic

  For the lease of a home: not enough

• private deed signed by the parties

  Signature: Handwritten on paper

  For the lease of a home: valid, as always

The definitions come from the EU eIDAS regulation (EU 910/2014, articles 3 and 26), which gives a qualified signature the effects of a handwritten one (article 25); the digital signature is defined in article 1 of the code.

A scanned signature pasted onto a PDF does not reveal changes made afterwards. A one-click signature, or one with a code sent by text message, counts as advanced only if it meets all four requirements: ask the provider in writing.

A digital signature is obtained from a qualified trust service provider (in Italy it qualifies with AgID, article 29 of the code), also in remote form. Anyone without one can sign on paper and post the original.

The Trieste angle: the certificate and tenants from elsewhere

With regulated rent, if the lease is drawn up without the assistance of the signatory organisations, the certificate of compliance is requested from one of them. The 2025 territorial agreement, filed with the Comune on 15 December, is strict (article 10): the certificate is valid and effective only if whoever issues it signs it with a qualified digital signature, and a certificate with a scanned handwritten signature is not valid. For the Agenzia delle Entrate (resolution 31/E of 2018), in leases drawn up without assistance the certificate is needed for the tax reliefs, including the 10% flat-rate tax (cedolare secca).

In Trieste, however, two agreements are in force, as the Comune states: the 2022 agreement, extended by other organisations on 11 December 2025, has its own certificate template (annex 4).

Then there are people signing from afar: the researcher arriving in two months, the tenant who lives in Ljubljana or Vienna. A qualified signature issued in another European Union country is recognised as qualified in Italy too (eIDAS, article 24a, inserted by regulation EU 2024/1183). A signature with a certificate from a provider established outside the Union counts as a digital signature only in the three cases of article 24, paragraph 4-ter, of the code, for example if the provider is qualified in a member state; otherwise an advanced signature, the article 20 signing process or paper remain.

How is a lease signed online registered?

Like any other: within 30 days of signing, or of the start date if earlier, even from home with the Agenzia delle Entrate's RLI web. RLI web accepts the copy of the lease only in TIF, TFF or PDF/A: if the signed file is in another format, attach a PDF/A copy. In some simple cases, listed on the Agenzia's page, attaching it is not compulsory.

If the tenant is not resident and has no Italian tax code (codice fiscale), registration is requested at an Agenzia office with form 69 instead of RLI, and form 69 also allows choosing the cedolare (resolution 5/E of 2023).

Stamp duty does not change because the lease is digital. In ruling 153 of 2026, on concession contracts of a public body issued electronically, the Agenzia excluded a flat-rate stamp duty: article 2 of the tariff of DPR 642/1972 applies, per sheet. According to the Agenzia's page that means €16 for every 4 written sides and in any case every 100 lines. With online registration, registration tax and stamp duty are paid by direct debit from a bank or post office account; with the cedolare secca they are not due.

Registration also gives a certain date against third parties (civil code, article 2704).

An example: landlord in Trieste, tenant in Ljubljana

Assumptions: a 3+2 at regulated rent under the 2025 agreement. The tenant is a Slovenian citizen, already has an Italian tax code and will move to Trieste in a month.

1. The text follows the ministerial model referred to by the agreement, and the tenant reviews it remotely.
2. The landlord signs with his digital signature, the tenant with her Slovenian qualified signature: in Italy it counts as qualified, and the lease has written form.
3. With the request on the agreement's form, the signed lease and a copy of his identity document, the landlord asks a signatory organisation for the certificate, which issues it with a qualified digital signature.
4. Within 30 days he registers with RLI web, attaches the PDF/A copy, chooses the 10% cedolare and pays neither registration tax nor stamp duty.
5. Nothing goes to the Questura: registration absorbs the notice of transfer of a building (decree-law 79/2012, article 2), and the tenant is an EU citizen.

With a tenant from a country outside the Union, a written notice to the public security authority would also be needed within 48 hours (legislative decree 286/1998, article 7): the Questura di Trieste wants Modello B, by certified email (PEC) or registered post, no later than 48 hours after the lease is signed.