The Treasury insists that these communications seek to encourage voluntary correction before a possible subsequent regularization. If the taxpayer considers their declaration to be correct, they do not have to modify it; if they detect an error, they can submit an amended declaration.
Treasury will send 130,000 letters to taxpayers
The Tax Agency is preparing to send about 130,000 warning letters to taxpayers during the 2025 Income Tax campaign. This is not an automatic penalty or an immediate assessment, but rather a notice for certain citizens to review their filed return and check if they have made any errors or omissions.
The shipment will be carried out in two phases. The first batch will arrive starting in mid-May and the second during the month of June, as taxpayers file their returns.
The objective of the Tax Agency is to reinforce voluntary compliance. That is, to notify before initiating a possible check or subsequent regularization. The idea is that the taxpayer has room to review the data and, if appropriate, correct the return.
Who can receive a letter from the Tax Agency
The letters are addressed to taxpayers who have already filed their income tax return and whose information may not match the data held by the Tax Agency.
In particular, the Treasury focuses on declarations in which the taxpayer has modified data that already appeared in the draft or in the tax data. This does not necessarily mean that they have done something wrong. There can be legitimate reasons to change information. But if the presented result is more favorable to the taxpayer and does not match the Treasury's data, the probability of receiving a notice increases.
The Tax Agency explains that, if the citizen believes their return was correct, they do not have to change it. But if upon reviewing the notice they detect an error or omission, they can correct it through the corresponding return.
What it means to receive one of these letters
Receiving a letter from Hacienda does not automatically equate to being sanctioned. Nor does it mean that the Tax Agency has already opened a full inspection.
The letter functions as a preventive notice. The Treasury informs the taxpayer that there is data that should be reviewed and gives them the opportunity to voluntarily correct it before the error can lead to a subsequent regularization.
The difference is important. One thing is a communication to review the declaration and another is a provisional settlement, a formal requirement or a sanctioning file. In this case, the purpose announced by the Tax Agency is to avoid errors and omissions that may end up generating problems later on.
What the taxpayer should do if they receive the letter
The first thing is not to ignore it. The taxpayer must review the submitted declaration and compare the data included with the tax information available at the Tax Agency.
If everything is correct and you can justify the declared data, you do not have to modify the declaration. But it is advisable to keep the documentation that supports that decision: certificates, justifications, contracts, receipts, deeds, proof of deductions, or any relevant document.
If upon reviewing the declaration you detect an error, the appropriate thing to do is to correct it as soon as possible.
Depending on the case, it may be necessary to file an amended or supplementary tax return. The key is to act before the Tax Agency initiates a regularization.
The data that is most convenient to review in the Tax Return
There are several especially sensitive sections. The draft tax return is a help, but it does not replace the taxpayer's responsibility. The Tax Agency reminds citizens each campaign that they must check that the information reflected matches their real situation.
Among the points that are worth reviewing are regional deductions, family situation, properties and cadastral references, rents, property transfers, contributions to pension plans, union dues, subsidies and public aid.
Attention should also be paid to aid such as the Youth Rental Bonus or the Cultural Bonus, when they must be declared as capital gains. An omitted detail or a misapplied deduction can explain the arrival of a warning letter.
The Tax Return Campaign Advances with Millions of Declarations
The 2025 Income Tax campaign began on April 8 and will run until June 30. Telephone filing through the "We Call You" plan is available from May 6, while in-person assistance at offices begins on June 1.
In the first month of the campaign, the Tax Agency had already received 7.98 million tax returns. Of these, 6.34 million were refund requests and 1.18 million had a result to be paid. The Treasury had refunded 3,147 million euros to more than 4.49 million taxpayers.
These figures also explain the volume of preventive notices. With millions of declarations already filed, the Tax Agency cross-references the declared information with available tax data and activates communications when it detects possible inconsistencies.
Can there be a penalty if the letter is ignored?
The letter is not a penalty in itself, but ignoring it can increase the risk if there really is an error in the declaration.
If the Treasury later detects that there was an omission or incorrect data that harmed the Administration, it can initiate a regularization and, depending on the case, demand the outstanding amount, interest, and a possible penalty.
That is why the preventive notice should be taken as an opportunity to review. If the taxpayer is right, they keep their declaration. If they are not right, voluntarily correcting can avoid a bigger problem.
What is the difference between complementary and corrective
The supplementary declaration is normally used when the error harms the Treasury and the taxpayer must pay more or receive less refund.
The rectification is requested when the error harms the taxpayer, for example, because they forgot to apply a deduction to which they were entitled or declared too much.
In any case, before submitting a modification, it is advisable to carefully review the reason for the notice and, if in doubt, consult with a tax advisor or the assistance channels of the Tax Agency.