Filing of supplementary self-assessments

What is a supplementary self-assessment?

Supplementary self-assessments are considered to be those that refer to the same tax obligation and period as others submitted previously and which result in a amount to be paid that is higher or an amount to be returned or offset that is lower than the amount resulting from the previous self-assessment , which will remain in the unaffected part.

When can a supplementary self-assessment be submitted?

A supplementary self-assessment may only be submitted for:

• Request a refund or compensation for a smaller amount.
• Make a deposit for a larger amount.

Therefore, if a taxpayer considers that a self-assessment has harmed his legitimate interests, he can only obtain compensation for the harm suffered by initiating a procedure to rectify the self-assessment.

Legal regulation

Both article 122 of Law 58/2003, General Tax Law, and article 118 of the General Regulations for the Application of Taxes, approved by RD 1065/2007, establish that self-assessments can only be complementary (they can never have a substitute character) that is, they always result in an amount favorable to the Administration, unlike what happens with declarations (for example, informative declarations) that can have a complementary or substitute character, since they do not have an associated payment or refund.

Characteristics of supplementary declarations

1. There must always be a previous self-assessment submitted which complements it. The amount of the initial self-assessment will be deducted from the tax quota resulting from the supplementary self-assessment.
2. If a supplementary self-assessment is submitted in relation to an obligation and period for which an improper refund has already been obtained, in whole or in part, the amount improperly obtained must be entered plus the fee that, where applicable, may result from the supplementary self-assessment.
3. It will be stated in its presentation that it is a supplementary self-assessment , the tax obligation and the period to which it refers. All data, both new and modified, and those included in the initial declaration must be entered.

Submission periods

They may be submitted within the deadline established for their submission or after it, provided that the Administration's right to determine the tax debt has not expired. In the latter case, they are considered untimely and if there is an amount to be paid, the surcharges provided for in article 27 of the LGT will be applied if there has been no prior request for its presentation.

Filing of supplementary self-assessments

The submission of a supplementary self-assessment is carried out when the error caused has been to the detriment of the Public Treasury. The situation must be regularized by submitting the corresponding form (the one originally submitted) for the year in which the error occurred, checking the "Additional" box .