The complementary declaration of the Income is an official document in fiscal matters that, as its name indicates, complements the common declaration and that includes the correction of errors, regularizing the lack of requested data or including required documents such as invoices.
The creation of a declaration of complementary type necessarily implies that it refers to a main declaration to which it corrects and that has been submitted in the same period and fiscal year . In addition, only those data that did not appear in the original or that must be corrected are included in this second presentation .
This type of declarations is quite common at the time in taxes such as personal income tax or VAT , especially on occasions when the return or the resulting final payment does not conform to reality and it is necessary to carry out a formal correction required by the Administration.
This last point is especially important, since it will only be possible to present a complementary declaration in those cases in which the public treasury is affected : either the refund has been greater than due or we have paid a lower amount of taxes than required. In the event that the error is foreign to the holder of the declaration, the claim process is carried out through other means, not through this type of documents.
The existence of this type of administrative tool facilitates the correction of frequent errors, especially taking into account that many declarations are made through the so-called self-assessment (professionals or tax technicians are not resorted to, but they do it personally).
A complementary tax return must be submitted according to deadlines previously set by the State and which normally vary depending on the reasons why a regularization is necessary. It will also be necessary to indicate the reference number of the initial declaration for the Administration to identify the correction , as well as to specify whether it is a declaration of this type or substitute.