You could be losing money to the IRS without realizing it. Submitting the declaration in 2026, relating to 2025 income, requires more than clicking “send”. Small lapses, data to be confirmed or poorly simulated options can translate into a smaller refund or even an additional amount to be paid to the State at the IRS.
According to Executive Digest, a website specializing in economics, which has followed the guidelines from the Tax and Customs Authority (AT), many taxpayers simply accept pre-filled data without rigorous verification. The process is increasingly simpler, but continues to require attention.
Starts before April
Preparation does not begin the moment you open the declaration.
In March, AT makes available the amounts of collection deductions calculated based on validated invoices. According to the same publication, it is essential to consult this information on the Finance Portal and confirm that all expenses are correctly classified.
Expenses for health, education, housing or residences can directly impact the final tax. If you detect errors, there is a specific deadline to complain. Skipping this step could mean forgoing deductions you would otherwise be entitled to.
Automatic Income Tax does not require verification
The automatic IRS has simplified the lives of many taxpayers. The declaration appears completed and you just need to confirm the data. However, this ease can create a false sense of security.
As explained by , it is essential to review each field, especially when there are changes in the family situation, additional income or changes in the household.
Simulating joint and separate taxation, when applicable, may reveal relevant differences in the final result. There are cases where choosing an apparently simple modality results in a lower reimbursement.
Capital gains and cryptoactives require extra care
Capital gains from the sale of shares, funds or other securities are not always intuitive.
As a general rule, these operations are taxed at the autonomous rate of 28 percent. However, there may be an obligation to combine, which changes the form of taxation. According to the same source, the decision whether to include or not can significantly influence the tax payable.
The same happens with cryptoassets. The duration of detention is decisive. In certain situations, there may be an exemption; in others, autonomous taxation applies or even classification in category B, if there is associated economic activity.
Deadlines that cannot be missed
The declaration is submitted between April 1st and June 30th, 2026. Afterwards, the Federal Revenue Service issues the settlement note, normally by the end of July.
If there is additional tax to be paid, the deadline extends, as a rule, until the end of August. Delivery after the deadline may generate fines provided for in the General Tax Offenses Regime.
But the biggest risk is not always the fine. It’s submitting an incomplete or poorly simulated declaration and losing money without realizing it.
Detail makes the difference
The IRS is not just an annual administrative procedure. It is time to settle accounts with the State.
Reviewing expenses, confirming personal data, analyzing the income framework and simulating different scenarios are steps that can make a difference in the final result.
It may seem like a simple process. And, in many cases, it is. But it is precisely in the small details that the differences between a maximized refund and a lost opportunity are hidden.
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