ISTAT Rent Adjustment: Tenants' Guide Italy

Rent updates (ISTAT) and local agreements (with attestation) 2 min read · published September 11, 2025

If, as a tenant in Italy, you receive a notice of ISTAT rent adjustment, it is important to know how to read the contract clause and which steps to take. This article explains in plain language what ISTAT indexation means, how to calculate the increase based on the official index, when adjustment is mandatory and how to check any territorial agreements or attestations. You will find practical instructions to record calculations, communicate with the landlord, request clarifications and, if necessary, defend your rights before the competent authorities. Examples, action templates and official references are included to help you manage the situation confidently.

What ISTAT rent adjustment means

ISTAT adjustment means updating the rent according to changes in the consumer price index. Methods are set out in the contract and by law; check the indexation clause in your contract to understand if and how it applies.[1]

The ISTAT index measures inflation and can increase the rent if provided for in the contract.

How to calculate the increase

To calculate the increase follow these points:

  • Check the adjustment clause in the contract.
  • Obtain the ISTAT index reported for the agreed period.
  • Apply the formula indicated in the contract to obtain the increase.
Keep calculations and documentation of communications between the parties.

Practical steps

Practical actions if you receive a request to adjust the rent:

  • Contact the landlord to request clarifications and the documentation of the attestation or territorial agreement.
  • Send a written communication with your calculations and request for discussion.
  • Keep receipts, messages and photos that document the condition of the property.
  • If no agreement is reached, consider recourse to the competent Court or the Justice of the Peace.
Respond within the indicated deadlines to avoid jeopardizing your rights.

Frequently Asked Questions

Can the landlord adjust the rent without my consent?
If the contract includes an indexation clause, the landlord can apply it in the agreed ways; otherwise an agreement between the parties is required.
Can I refuse an incorrectly calculated increase?
Yes, you can request clarifications and present your calculations; if the dispute continues you can turn to the judge.
Do I need to register the adjustment agreement?
If the contract is modified or a permanent variation is agreed, it is necessary to register the changes with the RLI Form.[2]

How to

  1. Check the adjustment clause in your contract.
  2. Calculate the increase using the official ISTAT index for the period.
  3. Send the landlord a written request with calculations and evidence.
  4. If you do not reach an agreement, consider legal action or mediation.

Key takeaways

  • Always check the contract clause before accepting an adjustment.
  • Document communications, calculations and receipts for every increase request.

Help and support


  1. [1] Normattiva
  2. [2] Agenzia delle Entrate
Bob Jones
Bob Jones

Editor & Researcher, Tenant Rights Italy

Bob writes and reviews tenant law content for various regions. They’re passionate about housing justice and simplifying legal protections for tenants everywhere.