Can the taxpayer rectify a self-assessment if you notice a mistake that affects you?

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Every taxpayer has the right to request the rectification of the self - assessments made by them via the Tax Administration, if it considers that somehow it affects their legitimate interests.
This right is assisted whether the reverse charge has made the realization of an undue income, or not, (see section 1.11).
What happens is that at first hand, the application involves the request for the return of undue payment, while on the other; it only involves the rectification of the error to avoid separate damage.

Whatever the content of the request (return of improper income or rectification of another error), the request must be made by the taxpayer before the Administration has practiced and notified the final settlement. And, in the absence of the latter, before operating the prescription (see section 7.2).

The administration is required to resolve the request. But if three months pass without notifying its decision, the taxpayer may consider it dismissed, and appeal against the implied rejection; or wait for the express resolution and appeal or not, depending on whether their content is favorable or not.