The taxpayer may, at any time prior to the date on which the prescription operates (see Chapter 8) and provided that the Administration has not made the final settlement of the tax, can submit supplementary declarations deemed appropriate.
Supplementary declarations are presented to modify the contents of one or more earlier and involve the taxpayer, paying an additional tax debt. Thus, if there has been no previous declaration, there is no question of supplementary declaration (but, where appropriate, a delayed declaration). And if the new declaration intended to rectify a previous one which effects the interests of the taxpayer, isn’t a supplementary declaration (the mechanism to correct such damage is described in section 1.6.).
The presentation of a supplementary declaration has the disadvantage of interrupting the prescription (it is an undesirable effect for the taxpayer), which implies that the administration again, have a period of five years for the verification and practice the final corresponding settlement (see section 7.3).
A characteristic of the supplementary declaration lies in the fact that additional tax debts, arising therefrom cannot be entered through the collaborating institutions (banks and savings banks), but in the existing funds in Delegations and tax offices. This characteristic affects complementary Statements made one month after the expiration of the statutory deadline for submission of the tax return.
Prior to the expiration of the statutory deadline for the declaration of any tax (e.g. 20th or 30th June, in the personal income tax) the taxpayer can file without negative consequences, as many supplementary declarations they wish to make. Supplementary declarations submitted after the deadline follows the procedure described in paragraph 1.6.