For those who have sent the 730 form and realize they have forgotten some data, as well as those who have missed the deadline entirely, there is still some time to get in order. As FiscoOggi explains, a first possibility is Income Pf: it must be presented by November 2nd. Attention: if the correction leads to a more favorable or "equal" tax result, there is also the option of a supplementary 730 which must be sent by October 26th via a Caf or a qualified professional.
For further information: Taxes, October 2026 deadlines: the complete calendar
In the case of integration which generates a greater credit (or a lower debt) or which leaves the tax unchanged, therefore, in addition to the Personal Income model it is possible to use the supplementary 730.
FiscoOggi reminds you that this hypothesis is valid for those who, after sending the form, realize that they have forgotten to indicate a deductible or deductible expense, an income already correctly taxed or other elements that would have given the right to a more favorable tax result. Taxpayers who fall under these conditions have until Monday 26 October 2026 to submit a supplementary 730 through a Caf or a qualified professional. The same possibility is also provided when the correction does not change the tax due.
For further information: Increases in prices of fuel and energy: impact of the war in Iran on Italians
The supplementary 730, the experts still remind us, can be used by those who have presented the form with the assistance of a Caf or a professional, but it can also be used by those who have independently sent the pre-compiled 730 through the Revenue Agency's telematic services. In these cases, explains FiscoOggi, "the taxpayer must provide the documentation necessary to verify the changes made and, if the original form was presented without the assistance of an intermediary, all the documentation relating to the declaration must be shown".
For further information: INPS payments October 2026, the dates to mark on the calendar
The Revenue Agency magazine also explains how to fill out the form. If the integration involves a greater credit, a lower debt or leaves the tax result of the return unchanged - explains FiscoOggi -, the taxpayer must present a new form complete in all its parts, indicating code 1 in the "supplemental 730" box on the frontispiece. To give a few examples, this includes cases in which you realize that you have not entered a health expense, mortgage interest or other charges that give you the right to a deduction or deduction.
As regards corrections favorable to the taxpayer, as an alternative to the supplementary 730 you can choose the path of the Personal Income model. “The declaration can be presented as a corrective within the deadline set for the Income model, therefore 2 November 2026, or subsequently by means of a supplementary declaration, within the time limits according to the rules established by law”.
Pay attention, then, to these cases: if the correction reveals a lower credit or a greater tax debt, the supplementary form 730 cannot be used and the taxpayer can only resort to Personal Income. If the correction results in an amount to be paid - explains FiscoOggi - it is necessary to proceed with the payment of the taxes due, the interest calculated at the legal rate and the penalties reduced through active repentance. “The regularization can be carried out either through a corrective declaration within the deadlines or through a supplementary declaration presented in subsequent years, within the limits established by law”.
