Income from work must be declared in the year in which it is due. However, if the company does not pay them at that time (due to liquidity problems, for example), the worker can declare them when they are collected, along with the withholding tax paid. To do this, according to the law, he must submit an amended income tax return for the year in which these arrears were due , and must do so within the period between the collection date and the end of the following tax return filing deadline . Filing this amended return does not entail the payment of late interest, surcharges, or penalties. However, to avoid issues with the Tax Agency, when submitting it, it is important to state the reason for the amendment in the income tax return form.

Now, when interpreting the above rule, many taxpayers believe that if, for example, in 2026 they collect arrears from 2025, the amended return for 2025 can always be filed until June 2027 (which is when the deadline for filing the 2026 return expires). However, this interpretation is not entirely correct:

Starting from April 8

• From April 8th include the arrears in the 2025 income tax return (if, for example, they are collected before June 30,2026 and the individual has not yet filed their 2025 return), or to submit an amendment to the 2025 return until June 30,2027 . Until April 7

• Until April 7th to include them in the 2025 income tax return, which is filed by June 30,2026 . That is the closest filing deadline; if the arrears are declared later, the Tax Agency may demand surcharges for filing late. . That is the deadline for the nearest filing date; if you declare delays later, the Treasury may require surcharges for doing so out of time.