Option changes

You may choose to present the most favorable taxation option. As a general rule, the choice of joint or individual income tax return filing is irrevocable once the statutory period for filing self-assessments has ended. 

If the change of option is due to a modification to the self-assessments already filed, the changes will be made, as appropriate, to the individual return of the taxpayer, the spouse, or any children with income, even if a joint return has been filed or is to be filed.

Once you have made the changes to your return, in "Return sections" you will select the option "Modify 2024 Income Tax Return already filed":

And in the window you will mark box 124:

When changing your taxation option from individual to joint, you generally don't need to enter any amounts manually, as it automatically includes receipt numbers, previous income (only income actually received will be counted), and previously agreed-upon refunds. Therefore, those requested by the taxpayer that have not been approved by the AEAT are not counted.

When changing the option from joint to individual, the amounts must be filled in manually, so the boxes will appear empty:

Therefore, each individual return will reflect the corresponding portion of the income actually incurred or the agreed refund from the joint return attributed to each taxpayer.

It is possible that not all members of the family unit, even if they have taxable income, are required to file a tax return.

Consequently, the corresponding portion of the income or refund from the joint declaration must be completed in each individual declaration, taking into account that the sum of the amounts recorded in the individual declarations must be equal to the amount of the original joint declaration.

Finally, the declaration(s) will be submitted. Unlike the previous cases of corrective self-assessments, the change of option will be submitted from the declaration type you wish to choose.