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Form 100. Personal Income Tax Return 2024

3.2.1. Family unit

For the purposes of personal income tax, there are two types of family unit:

  • 1 Modality: family unit consisting of spouses

    When there is a marriage (and the spouses are not legally separated), the family unit will be made up of the spouses and, if any:

    1. Minor children (except those who live independently with the consent of their parents)

    2. Children of legal age who are legally incapacitated and subject to extended or renewed parental authority. As of the entry into force of Law 8/2021 amending the Civil Code, those children of legal age with disabilities for whom a representative guardianship has been established by court order will also be included.

  • 2 Modality: family unit in case of legal separation or non-existence of marriage

    When there is no marital bond or the spouses are legally separated, and, in addition, the taxpayer has minor children or children subject to extended parental authority, the family unit will be comprised of the parent (father or mother) with all the children who live with him of those mentioned above; that is to say:

    1. Minor children (except those who live independently with the consent of their parents)

    2. Children of legal age who are legally incapacitated and subject to extended or renewed parental authority. As of the entry into force of Law 8/2021 amending the Civil Code, those children of legal age with disabilities for whom a representative guardianship has been established by court order will also be included.

In cases of legal separation or absence of a marital bond in which custody of the children is shared, if there is no justification for the existence of mutual agreement between the parents for one or the other to qualify for "joint taxation" (a mutual agreement that must be reached prior to filing the tax returns), both parents, and also all the children, must pay taxes under the "individual taxation" regime. TEAC Resolution of July 19, 2024, Claim number 00/02172/2023, filed in an appeal for the unification of criteria.

No one may be part of two family units at the same time.

The determination of the members of the family unit will be made taking into account the situation existing on December 31 of each year.

People who are part of a family unit have the option of filing joint personal income tax returns.