ISA 2026: how to request precalculated data and manage the single mandate

Context

In brief

• New rules for precalculated ISA 2026 data
• Integrated single mandate
• Operational impact for intermediaries

Key facts

• What: New methods to access precalculated ISA 2026 data
• When: Provision of 13 April 2026
• Where: Italy
• Who: Italian Revenue Agency
• Amount: Not specified

The provision of 13 April 2026 stabilizes the methods to access precalculated data for the ISA 2026, introducing full integration with the single mandate and new rules for punctual and mass requests. This change has a significant operational impact on intermediaries and professional firms assisting cross-border workers.

To determine the tax reliability score, in addition to the data entered in the ISA Models, further information, referred to as 'precalculated variables', made available by the Italian Revenue Agency, is required. These variables are provided per 'ISA position' and are used for the application of the ISA through the appropriate software program.

What are the precalculated ISA variables

In addition to the data transmitted through tax declarations, interested taxpayers must use further data provided by the Italian Revenue Agency. These data, identified in the Technical and Methodological Note of the precalculated variables, are attached to the approval decrees and amendments to the ISA applicable in the relevant tax periods.

How to request precalculated data

With the provision of 13 April 2026, the Italian Revenue Agency has structurally defined the methods through which taxpayers and intermediaries can acquire the 'additional data'. This change simplifies the process of accessing precalculated data, making it more efficient and integrated with the single mandate.

For cross-border workers who work in Canton Ticino and reside in Italy, it is crucial to understand how these new rules may affect their tax situation. Access to precalculated data is essential to correctly determine the tax reliability score, which can have repercussions on withholding taxes and AVS and LPP contributions.

Impact on cross-border workers

Cross-border workers must be aware of the new procedures for requesting precalculated data and managing the single mandate. This process can influence their income tax return and the determination of the tax reliability score, which in turn can affect withholding taxes and pension contributions.

Conclusion

The new rules for precalculated ISA 2026 data represent a significant change in the process of determining the tax reliability score. For cross-border workers, it is essential to understand these new procedures and how they may affect their tax situation. We recommend consulting a professional in the field to ensure compliance with the new regulations.

Operational details

Practical Analysis

The new rules for precalculated ISA 2026 data introduce a series of changes that can have a significant impact on the tax management of cross-border workers. It is important to understand how these changes can influence the determination of the tax reliability score and, consequently, withholding taxes and pension contributions.

Before/After Comparisons

Before the measure of April 13, 2026, access to precalculated data was less structured and more complex. With the introduction of the single delegation and the new rules for punctual and mass requests, the process has become more efficient and integrated. This change simplifies the lives of cross-border workers and intermediaries, making it easier to manage tax declarations.

Concrete Scenarios

Suppose a cross-border worker who works in the Canton of Ticino and resides in Italy needs to determine their tax reliability score. With the new rules, the cross-border worker or their intermediary can easily access precalculated data through the single delegation, simplifying the income tax declaration process.

Comparison with the Previous Situation

Before the measure of April 13, 2026, access to precalculated data was more complicated and time-consuming. With the new rules, the process has become more efficient, reducing the time and effort required for tax management. This is particularly advantageous for cross-border workers, who often have to manage complex tax declarations in two different countries.

Impact on Double Taxation

The new rules for precalculated ISA 2026 data can also influence the management of double taxation. A more accurate tax reliability score can help avoid situations of double taxation, ensuring that cross-border workers pay the correct taxes in both countries.

Conclusion

The new rules for precalculated ISA 2026 data represent a significant step forward in the tax management of cross-border workers. With a more efficient and integrated process, cross-border workers can better manage their tax declarations and avoid situations of double taxation. It is crucial that cross-border workers are aware of these changes and prepare adequately for the 2026 income tax declaration.

Useful planning tools

To estimate your pension strategy, use the pension planner and the pillar 3 simulator.

Key points

Concrete Action

For cross-border workers employed in the Canton of Ticino and residing in Italy, it is essential to follow a series of concrete steps to correctly manage the precalculated ISA 2026 data and the single mandate. Here is a step-by-step guide to ensure compliance with the new regulations.

Step 1: Verification of Precalculated Data

The first step is to verify which precalculated data is necessary for determining the tax reliability score. This data is provided by the Italian Revenue Agency and is specific to each 'ISA position'.

Step 2: Access to Precalculated Data

With the provision of April 13, 2026, accessing precalculated data has become simpler thanks to integration with the single mandate. Cross-border workers or their intermediaries can access the precalculated data through the Italian Revenue Agency's portal.

Step 3: Entering Data into the ISA Model

Once the precalculated data is obtained, it must be entered into the ISA Model. This step is crucial for correctly determining the tax reliability score. It is important to carefully follow the instructions provided by the Italian Revenue Agency to avoid errors.

Step 4: Verification of the Tax Reliability Score

After entering the precalculated data into the ISA Model, it is necessary to verify the tax reliability score. This score can influence withholding taxes and social security contributions, so it is fundamental to ensure it is calculated correctly.

Step 5: Submission of the Tax Return

Finally, it is necessary to submit the tax return, including all precalculated data and the tax reliability score. It is important to respect the tax deadlines to avoid penalties.

Useful Tools

To facilitate the process, you can use the tax calculator available on our website. This tool can help determine the tax reliability score and verify the correctness of the data entered in the ISA Model.

Conclusion

By following these steps, cross-border workers can correctly manage the precalculated ISA 2026 data and the single mandate, ensuring compliance with the new tax regulations. It is fundamental to stay updated on the latest tax news and use useful tools to facilitate the tax return process.

Source: commercialistatelematico.com