8.10.1. Supplementary tax return

Errors or omissions in declarations already submitted that have resulted in a lower payment than legally due or a higher refund than due must be rectified by submitting a supplementary declaration-settlement to the one originally submitted.

Any situations or circumstances that arise which result in the loss of the right to a reduction or exemption already applied in a previous declaration must also be regularised by submitting supplementary declarations-settlements.

However, the loss of the right to certain deductions must be regularized in the declaration of the fiscal year in which the non-compliance with any of the requirements for the consolidation of the right to said deductions occurred.

1. Supplementary declarations without penalty, interest or surcharge
2. Supplementary declarations including late payment interest
3. Completion