The Synthetic Index of Reliability expresses an overall assessment on the reliability of taxpayers' tax behavior and involves an audience of approximately 4 million subjects engaged in business activities and self-employment.


The ISA elaboration and application project shows major methodological innovations in the analysis of taxpayers' behaviors, with the aim of defining the level of fiscal reliability towards the Tax Authorities.

The Synthetic Index of Reliability (in Italian abbreviated as ISA) was introduced in the Italian system in 2016.

The discipline was subsequently completed by Law no. 96 of 2017, the implementation of which has incorporated the indications coming from the business world, from professional associations and universities, and is aimed at improving the quality of the relationship between taxpayers and Tax Authorities.

The introduction of ISAs is part of the tax reform launched in recent years aimed at outlining a new system of relations between Tax Authorities and taxpayers, encouraging tax compliance, transparency and dialogue.

The definition path of ISAs, from the experimental phase to their implementation, was based on the ongoing collaboration with entrepreneurial and professional associations and Tax Authorities in order to obtain an outcome able to establish a shared compliance system.

SOSE acted as a "third party", i.e. represented an impartial, “scientific”reference point, which mediated different needs and brought innovative solutions for both tax payers and Tax Authorities.


ISA Document