Filing taxes after divorce: what the Tax Agency needs to know
Tax season is a chore nobody looks forward to, but when you are divorced and have children it becomes a minefield of unanswered questions. Who claims the child tax allowance? What happens with child support? Can you file jointly with your children? Which expenses are deductible? These are questions that affect hundreds of thousands of taxpayers every year in Spain, and getting them wrong can lead to penalties from Hacienda or to missing out on tax benefits you are legally entitled to.
This guide explains, step by step and in plain language, how to file your income tax return in 2026 if you are divorced or legally separated and have children. Practical examples and the most common mistakes are included so you can avoid them.
After a divorce, each parent files their own individual income tax return. A joint return is only possible with your children if you have sole custody and form a single-parent household unit.
2026 tax changes for divorced families
Every year, tax rules are updated and directly affect how divorced or separated families are taxed. Although the general principles of the IRPF (Spanish personal income tax) remain stable, several aspects are worth reviewing each tax season to avoid missing benefits or making errors.
Personal and family minimum allowances are reviewed periodically. The amounts for the child allowance, the allowance for dependant ascendants, and the disability supplements can change from one tax year to the next. Before filing, always confirm the current figures on the Agencia Tributaria website or with your tax advisor, since using figures from the previous year can cause discrepancies.
Another important point is the improvements to digital filing. The Agencia Tributaria's Renta Web tool adds new features every year that simplify the process. Recent campaigns have improved automatic import of tax data, real-time error validation, and the ability to import prior-year draft returns. For divorced families, this makes it easier to verify that the data relating to children — custody arrangements, allowances applied, support payments — matches what the other parent has declared.
Finally, pay attention to any changes in regional deductions and to the Agencia Tributaria's criteria on specific situations such as shared custody or child support annuities. Reading the informational notes the Agencia Tributaria publishes at the start of each campaign will give you a clear picture of what has changed compared to the previous tax year.
Individual or joint return: what are your options
After divorce, always individual (with one exception)
Once the divorce or legal separation order is final, joint taxation as a couple is no longer possible. Each parent files their own individual return. There is no option to file jointly with your ex-partner, regardless of the custody arrangement.
There is, however, one important exception: the parent who has sole custody may choose to file jointly with the children, forming a single-parent household unit. This entitles that parent to a reduction of 2,150 euros on the taxable base.
Shared custody: what happens
When custody is shared, both parents live with the children throughout the year. In this case, only one parent can choose to file jointly with the children in any given tax year. The law does not require them to alternate, but it is common practice for both parents to agree to take turns with the joint return each year so that both can benefit from the household unit reduction.
If no agreement is reached, only the parent with whom the children are living at the tax accrual date (31 December of the tax year) may file the joint return.
The child tax allowance: how it is split
The child tax allowance is one of the most significant tax benefits when you have children. For 2026 the amounts are:
- First child: 2,400 euros per year
- Second child: 2,700 euros per year
- Third child: 4,000 euros per year
- Fourth child and beyond: 4,500 euros per year
- Children under 3 years old: additional supplement of 2,800 euros
Sole custody
When one parent has sole custody, the full child tax allowance applies to that parent, provided the child lives with them and does not earn more than 8,000 euros per year or file their own return with income above 1,800 euros.
Shared custody: split 50/50
Under a shared custody arrangement, the child tax allowance is divided equally between both parents. With one child, each parent claims 1,200 euros. With two children, each parent claims 2,550 euros (half of 2,400 + 2,700).
This split is automatic and cannot be altered by private agreement. Even if you and your ex agree that one of you will claim 100%, Hacienda will not accept it. The IRPF rules are clear: when custody is shared, the allowance is prorated.
Child support: tax treatment
For the payer: not deductible, but there is a benefit
The child support you pay is not a deductible expense under the IRPF. You cannot subtract it from your taxable base as you would a donation or a business expense. However, the law provides an alternative mechanism: child support annuities are taxed separately from the rest of your income.
This means the child support amount is subject to the IRPF rate scale independently of your other income. In practice, because it is taxed separately, the lower tax brackets apply to that amount, which can result in a meaningful tax saving. This benefit applies when the support payment has been set by a court order.
For the recipient: not taxable
The child support you receive for your children is exempt from IRPF. You do not need to declare it as income or pay tax on it. The law treats this amount as being entirely devoted to covering the children's needs.
Spousal maintenance: a different treatment
Spousal maintenance paid between ex-spouses (as distinct from child support) has a clear and more favourable tax treatment. For the payer, it is a reduction on the taxable base — it directly reduces the amount on which the tax is calculated. For the recipient, it is taxed as earned income.
This distinction matters. Child support and spousal maintenance are separate concepts with different tax treatments. Confusing them is one of the most common mistakes.
Practical examples: 50/50 shared custody vs sole custody
Understanding the theory is useful, but seeing how it applies in real situations helps avoid mistakes. Below are two simplified practical examples that illustrate the main tax differences between shared custody and sole custody.
Case 1: 50/50 shared custody. Ana and Carlos have two minor children and share custody equally. Both are employed. The total child tax allowance for two children is 5,100 euros (2,400 + 2,700), so each parent claims 2,550 euros on their individual return. This year, Ana and Carlos have agreed that Carlos will file the joint return with the children, benefiting from the 2,150-euro reduction on the taxable base. Next year it will be Ana's turn. As for child support, since custody is shared and each parent covers expenses during their own time with the children, no judicial child support order exists and neither parent applies the child support annuity regime. If both parents earn similar incomes, alternating the joint return allows the tax benefit to be shared equitably over time.
Case 2: Sole custody. Laura has sole custody of her three children. Pedro, the father, pays court-ordered child support of 600 euros per month. Laura claims the full child tax allowance: 9,100 euros in total (2,400 + 2,700 + 4,000). In addition, as a single-parent household unit, she can choose to file jointly with her children and claim the 2,150-euro reduction. Pedro, for his part, cannot claim any child tax allowance, but the 7,200 euros of annual child support is taxed as a child support annuity with a separate rate. This means those 7,200 euros are subject to the IRPF scale independently of the rest of his income, which in practice can save him several hundred euros compared with everything being taxed together.
These examples are approximate and illustrative. Every personal situation has nuances — income levels, regional deductions, other sources of income — that can alter the final result. If in doubt, a tax advisor specialising in family law can review your specific case and optimise your return.
Regional deductions: do not overlook them
In addition to the national tax benefits, most Spanish regions (autonomous communities) offer specific deductions that may apply after a divorce:
- Nursery expense deduction: Available in regions such as Madrid, Cataluña, and Andalucía. If you pay nursery fees for your child, you may deduct part of the cost.
- School supplies deduction: Some regions allow deductions for textbooks and school materials.
- Single-parent family deduction: Regions such as Cataluña and Valencia offer additional deductions for single-parent families.
- Primary residence rental deduction: If you are renting your home following the divorce, check whether your region provides this deduction.
Review your region's deductions every year, as they change frequently and can add up to significant savings. If you manage expenses through a shared bank account for the children, bear in mind that transactions on that account may also have tax relevance.
Financial support and deductions for separated families
Beyond regional deductions, there are national tax benefits that many separated families are unaware of or do not apply correctly. The child tax allowance is the best known, but it is not the only one. Families that qualify as large families — three or more children, or two if one has a disability — can claim a deduction of up to 1,200 euros per year (2,400 euros for a large family of special category). Likewise, single-parent families with two or more children are entitled to a similar deduction. These amounts can be received in advance, at 100 euros per month, by applying to the Agencia Tributaria.
Child support deserves a specific mention among tax benefits. Although it is not directly deductible for the payer, the child support annuity regime with a separate tax rate can significantly reduce the IRPF bill. For this benefit to apply, the support must be established by a court order. Voluntary payments or private agreements not formalised through the courts do not qualify for this tax treatment. As for extraordinary expenses — orthodontics, summer camps, extracurricular activities not covered by the support payment — although they do not generate a specific deduction in their own right, documenting them correctly is essential for demonstrating the real financial situation to Hacienda and for justifying possible regional deductions linked to educational or healthcare expenses for the children.
Finally, remember that regional deductions vary enormously from one autonomous community to another. Regions such as Madrid, Cataluña, Andalucía, and the Comunitat Valenciana offer specific deductions for single-parent families, educational expenses, and childcare for children under three that can add several hundred euros in additional savings. Consulting your region's tax guide before filing is a step you should not skip.
Common mistakes in your tax return after divorce
1. Claiming the full child tax allowance under shared custody
This is the most common mistake. Many taxpayers with shared custody claim 100% of the child tax allowance instead of 50%. Hacienda routinely catches this when cross-checking both parents' data and issues a supplementary tax assessment with late-payment interest.
2. Trying to deduct child support as an expense
Child support paid to children is not deductible. Some taxpayers include it as a reduction on the taxable base, confusing it with spousal maintenance. The result: an incorrect return and a possible penalty. If you are unsure which expenses are deductible, bear in mind that extraordinary child expenses may receive different tax treatment.
3. Failing to document shared custody
For Hacienda to accept the 50/50 split of the child tax allowance, you need to prove that you have shared custody by providing the court order or the divorce settlement agreement. If you cannot produce this documentation when requested, you will lose the benefit.
4. Forgetting to declare spousal maintenance received
If you receive spousal maintenance from your ex-spouse, you must declare it as earned income. Omitting this income is a mistake Hacienda detects easily, since the payer declares it as a deduction and the Agencia Tributaria cross-references the data.
5. Not keeping receipts for children's expenses
Even though child support is not deductible, expenses you incur directly for your children can be relevant for regional deductions or for justifying the tax treatment applied. Keeping a detailed record of your children's expenses not only helps you manage shared expenses with your ex, but also protects you if Hacienda asks for evidence.
Keeping receipts for all expenses related to your children for at least four years is a legal obligation, but also a protective measure. A digital record is more reliable than a box of paper receipts.
Niddo as a tool for your tax return
One thing many separated parents discover too late is that an organised record of children's expenses can be very useful when filing your tax return. If you need to justify deductions for nursery fees, school supplies, or medical expenses, having each expense documented with a date, amount, and receipt makes the process significantly easier.
Niddo lets both parents log every expense, categorise it, and attach a photo of the receipt. When tax season arrives, you simply look up the expense history by category and export the information you need. It is a practical advantage that goes well beyond day-to-day management of shared expenses.
File your return with confidence
Your income tax return after a divorce does not have to be a headache. Knowing the rules, understanding which benefits you are entitled to, and avoiding the most common mistakes will save you money and stress. If your tax situation is complex, consulting a specialist in family tax law is an investment worth making.
And to keep your children's day-to-day expenses always in order, download Niddo for free and have all your financial information organised, accessible, and ready whenever you need it. Because a good expense record does not just prevent conflicts with your ex — it also simplifies your dealings with Hacienda.
