The Synthetic Index of Reliability (in Italian abbreviated as ISA) 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.
ISA is calculated as the arithmetic average of a set of elementary indicators and represents the position of the taxpayer with respect to these indicators by attributing to the subject a synthetic value ranging between 1 and 10. The lower the value of the index, the lower the tax reliability of the subject. The higher the value, the higher the tax reliability of the subject.
The elementary indicators used for the calculation of the summary index of tax reliability are divided into two groups: elementary indicators of reliability and elementary indicators of anomaly.
These indicators take into consideration:
- The level of reliability of accounting and structural data declared by taxpayers
- The reliability of information related to typical aspects of the activity
- The correspondence of the declared ISA data with the previous years and with the information inferable from other sources
Taxpayers with a high degree of reliability will have access to a multi-tiered reward system, which entails a number of benefits for taxpayers.