Unmarried with children: Filing your income taxes in Spain

Filing your annual income tax return (la Declaración de la Renta) can be confusing, especially if you have children and are not married. 

Unmarried parents in Spain face unique tax considerations, from choosing the right filing status to claiming deductions for dependents. 

This guide will explore how to file income tax returns when having children as an unmarried parent, explaining your options and tax implications in a friendly, supportive way. We’ll cover everything you need to know: 

• your tax status
• whether you must include your kids on your return
• eligibility rules 
• available deductions and allowances
• individual vs. joint filing
• and special situations like custody arrangements and child support. 

By the end, you’ll understand how to optimize your tax return as an unmarried parent with children, and we’ll highlight how Xolo’s tax service in Spain can help ensure you file correctly and get all the deductions you deserve.

Tax implications of being an unmarried parent with children

Being an unmarried parent in Spain affects your income tax filing in several ways. 

Spanish tax law recognizes different types of family units, which determines how you can file and what deductions you may claim. If you’re not married, you cannot file as a married couple, but you may still form a family unit with your child(ren) in certain cases. Specifically, Spain considers a “single-parent family unit” to be one parent plus their children living with them, which can qualify for particular tax benefits. 

However, if you live with the other parent of your child (without being married), the tax office will not treat you as a single-parent family for certain benefits. In practice, this means unmarried couples must plan carefully: only one parent can claim the family unit with the children, and the other will file as an individual.

In general, your personal allowance (the tax-free amount every taxpayer gets) remains the same as any single taxpayer. But having dependent children can increase your allowances and give you access to extra deductions. It’s important to understand that in Spain each person usually files their own tax return (including children if they have income), but you’ll want to include your kids in your return as dependents if you’re eligible, because it can significantly reduce your tax bill. We’ll explain how to determine your status and take advantage of all the tax breaks available to unmarried parents.

Identifying your tax status as an unmarried parent

What is your filing status when you’re an unmarried parent? In Spain, your filing status isn’t explicitly “single parent” on the form, but the concept comes into play when choosing between an individual or joint tax return. 

As an unmarried parent, you are essentially considered single for tax purposes. There are two family unit categories in Spanish tax law: (1) Married couples (plus their children), and (2) Single-parent families (one parent with children). Since you’re not married, you fall under the second category––a single-parent ––if you have qualifying dependent children.

Being recognized as a single-parent family unit means you have the option to file a joint return with your children (we’ll discuss this option in detail later on). Importantly, only one parent can claim that single-parent family unit status. For example, in an unmarried couple living together with children, only one of the parents can file a joint return that includes the kids; the other parent must file individually. You cannot both file one combined return since there is no legal marriage, and the tax law doesn’t allow two unmarried adults on the same tax return. 

The TL;DR? You have to decide which parent will claim the children as part of the family unit for tax purposes.

If you are separated or divorced (and not remarried), and you have the kids living with you, you generally qualify as a single-parent family unit on your own. In cases of shared custody where the children split time between parents, the tax authorities only allow one parent per year to use the joint/single-parent filing status with the children. Often, parents with joint custody choose to alternate who claims the joint return (family unit) each year––one year you include the kids on your return, the next year the other parent does, and so on––so that both parents benefit over time. 

Identifying your status correctly is the first step, as it determines what choices you have when filing.

Is it necessary to include your children when filing your taxes?

If you have dependent children, you might wonder if you are required to include them on your tax return. 

The short answer is yes––if they qualify as your dependents, you should include them, because it directly affects your tax calculation and it’s to your advantage. In Spain, including children on your return means claiming them as part of your family unit in the tax form’s personal details section. By doing so, you can apply the corresponding tax allowances for having children (the mínimo por descendientes) and any applicable deductions.

That said, it’s only mandatory to include them if they meet the criteria to be considered your dependents. If your son or daughter is financially independent or otherwise doesn’t qualify (see the next section for criteria), then you cannot include them on your return. But if they do meet the requirements, you will want to list them because you’ll benefit from significant tax reductions and credits by doing so. The tax agency’s draft (borrador) of your Renta return will usually automatically populate your children’s information if they have it, but you should double-check and add any missing details (such as a new baby born in the tax year).

Including your children is done in the datos identificativos (Identification details) section of the income tax return form. You will provide each child’s information (name, date of birth, tax ID number, etc.) and indicate factors like if they are under 25 and their income level. If your child earned any income during the year, you’ll also note that and whether it exceeds the threshold (e.g. a summer job income). Keep in mind that if a child has substantial income of their own, they might need to file their own return, and this can affect whether you can count them as dependent in your tax unit.

In summary, you are not legally penalized for not listing a qualifying child, but you would be leaving money on the table by missing out on tax allowances. As long as your children are eligible, it’s highly recommended (essentially required for optimal tax results) to include them on your declaration. This will ensure you get the increased family allowances and any deductions for which you qualify, reducing your payable taxes.

Eligibility criteria for including children in the Renta declaration

Not all children can be included on a parent’s tax return––they must meet certain eligibility criteria to be considered part of your family unit for tax purposes. In Spain, the rules for including children on your Renta are quite clear:

• Age: Your child must be under 25 years old as of the tax year (or of any age if they have a qualifying disability).
  
  
• Living with you: The child should live with you or be financially dependent on you. This typically means the child resides in your household for most of the year. If a child lives independently (with parental permission) or primarily with the other parent, they may not count as part of your unit in the same way. For separated parents, generally the parent who has custody or with whom the child lives gets to include them.
  
  
• Income of the child: The child must not have had annual income over a certain threshold. Currently, a child who earned more than €8,000 in the year cannot be claimed as a dependent for these tax purposes. Similarly, if the child filed their own income tax return and had income over €1,800, they might be considered independent for tax.
  
  
• Shared custody considerations: In cases of shared custody between unmarried/separated parents, the criteria above still apply for each parent. However, both parents cannot claim the same child in the same tax year.
  
  

If your situation meets these requirements – e.g. your children are under 25, living with you, and not earning above the limit – then you are eligible to include them on your Renta declaration as dependents. You’ll indicate this on the tax form as mentioned earlier. The benefit of doing so is that you can then access the tax reductions for children, which we’ll detail next. If your child does not meet these criteria (for instance, an older working child), they should file their own tax return if required, and you would not list them as your dependent in your filing.

Tax deductions and available allowances for unmarried parents

One of the biggest advantages of including qualifying children on your tax return is gaining access to various tax deductions and allowances created for families. 

Whether you are married or not, if you have dependent kids, Spanish tax law provides several ways to reduce your tax bill. While many exist, these are the key benefits you should consider first:

Personal allowance for children (Mínimo por descendientes): 

For each child that qualifies as your dependent, you get to increase the tax-free portion of your income. 

This works as a tax base reduction (similar to an allowance) just for having a dependent child living with you. The amounts are: €2,400 for the first child, €2,700 for the second, €4,000 for the third, and €4,500 for each subsequent child. 

These amounts are fixed by law and essentially raise the threshold of income on which you start paying taxes. In addition, for each child under age 3, there is an extra allowance of €2,800 per child (this is an increase to the above amounts for very young children). 

Example: You have two children, ages 5 and 2: Your total mínimo por descendientes: 7,900 EUR off your taxable base––2,400 (child one), 2,700 (child two) and a 2,800 bonus for a child under 3 years of age.

Joint filing reduction (for a single-parent family unit): 

If you qualify as a single-parent family and choose to file a joint return including your kids (more on this choice later), you receive an additional tax base reduction of €2,150 per year . 

This is essentially a bonus reduction for being an unmarried parent supporting a family. Note that this specific reduction is only applicable if you are not living with the other parent of the children. It’s meant for single parents (unmarried, widowed or legally separated) who are the sole adult in the household. 

If you live with your partner (but are unmarried), you cannot take this single-parent reduction.

Working mother deduction (Deducción por maternidad): 

This is a well-known tax credit for mothers (and in certain cases, adoptive fathers) who are employed or self-employed and have children under 3 years old. 

If you are a working mom with a young child, you can get a tax credit of up to €1,200 per year, per child under 3. This credit is actually given regardless of marital status––single moms and married moms alike can claim it––but it’s worth highlighting because it’s very common. You must be paying into Spanish Social Security (or receiving unemployment benefits) to be eligible. 

The working mother deduction can be received in one lump sum as a credit on your tax return, or you can opt for monthly advance payments of €100 throughout the year. Essentially, Hacienda (the tax agency) will pay you €100 a month for each young child if you apply, which totals €1,200 a year. This helps working parents cover childcare costs. Remember to mark the corresponding box for this deduction (casilla 611 on the tax form) or submit Model 140 to get the advance payments.

Large family deduction (Deducción por familia numerosa): 

Spain provides a tax credit for large families. A “large family” is usually defined as having three or more children (or two children if one has a significant disability, and there are other special cases).

 If you hold a Familia Numerosa certificate, you can claim a tax credit of €1,200 per year for a general large family (3–4 kids), or €2,400 per year for a special large family (5 or more kids). This credit is available to any qualifying family regardless of marital status; single parents with three or more kids can get it too. Moreover, for each child above the minimum needed to qualify as a large family, the credit increases by an additional €600. 

For example, if you have four children, that’s one more than the basic “large family” of three, so you’d get €1,200 + €600 for a total €1,800 credit. These credits can also be taken as monthly advance payments (like the maternity one) if you prefer, by filing the appropriate form.

Single parent with two children (Ascendiente con dos hijos) credit: 

There is a special tax credit of €1,200 per year that was introduced to support single parents with two children. 

This essentially extends a benefit similar to the large family credit to single-parent families that have only two children. To claim this, you must be unmarried (or legally separated) with two dependent children and not receive child support payments from the other parent (because if you do, that’s handled differently). You also need to be working, on an unemployment benefit, or a pensioner (similar conditions to the working mother deduction). 

In practice, this means if you are raising two kids on your own and the other parent is not contributing via court-ordered alimony, you can get this €1,200 credit. It cannot be combined with the large family credit––it’s one or the other. For example, a divorced mom of two who has sole custody and no support could claim €1,200 annually under this scheme. Like others, this can be claimed in advance monthly (€100/month) by submitting Modelo 143 to the Tax Agency.

Childcare expenses Deduction: 

There is an additional deduction of up to €1,000 for childcare (guardería) expenses for children under 3, which complements the working mother deduction. 

Essentially, if you pay for daycare or preschool for your child under the age of 3, you might get an extra credit (on top of the €1,200) up to this amount. This is calculated based on actual expenses and has certain limits and requirements (e.g. the childcare center must be registered, etc.). It’s something to keep in mind to further reduce your tax if it applies.

Regional deductions: 

Some autonomous communities in Spain offer their own tax deductions for having children, birth/adoption, or single-parent families. 

These vary by region. A region might have a one-time deduction for a new baby, or a small deduction for single-parent households beyond the state-level ones. It’s worth checking your autonomous community’s tax deductions (deducciones autonómicas) to see if there are extra benefits you can claim locally. These are applied in the regional section of the income tax form.

As an unmarried parent, you are entitled to all the above benefits just as any other parent would be, provided you meet the specific conditions. The key difference for unmarried parents is making sure who claims which child if both parents are in the picture, and understanding the unique credits aimed at single-parent situations (like the €2,150 joint filing reduction and the €1,200 single-parent credit). By claiming your children and these tax breaks, you can significantly lower your tax burden – often saving hundreds or thousands of euros. Next, let’s look at how you can file your return, whether individually or jointly, to maximize these benefits.

Filing options for unmarried parents: Individual vs joint returns

When it comes to actually filing your income tax return as an unmarried parent, you have to choose between two modes: individual filing or joint filing. Understanding these options is crucial:

• Individual returns: Filing individually (declaración individual) means you report only your own income and your share of deductions/allowances. If you’re unmarried, this is the default mode––you file as a single taxpayer. 

You can still include your children as dependents in an individual return to get the child allowances and relevant deductions discussed earlier. Most unmarried parents will file individual returns, especially if both parents are working and sharing custody (since both can’t file jointly together). If you and the other parent are unmarried and live together, in most cases each of you will file an individual return, and typically you would split the child-related allowances. 

Individual filing is straightforward and often makes sense if both parents have moderate to high incomes, because each gets to use part of the child allowance and their full personal allowance separately.

• Joint return with children: Joint filing in Spain is not limited to married couples. A single parent with children can opt to file a joint return (declaración conjunta), which combines all income of the family unit on one tax declaration. 

In your case, the family unit would be you and your child(ren), since there is no spouse. Why do this? Joint filing entitles you to that special €2,150 single-parent reduction off your taxable base in addition to the child allowances. It also pools incomes and deductions together. If you are the only earner in the family or if your income is much higher than any small income your child might have, a joint return can reduce tax because of the way the progressive tax rates apply on a combined base (and the extra reduction).

Caveat and scenarios to consider when choosing between joint or single filings

Example 1: If the other parent lives with you (unmarried partners cohabiting), you cannot both file one joint return. Only one of you can claim a joint return with the children, and the other must file individually. 

The one who does the joint return gets the €2,150 reduction but the other parent then cannot claim the children’s allowances on their return (because the kids are considered part of the other taxpayer’s family unit for that year). This situation needs a bit of number-crunching: sometimes it’s optimal for the higher earner to claim the joint family unit (to use the allowances and reduction against their higher income), while the other parent files alone with just the personal allowance. 

In other cases, it might be better for both to file individually and share the child allowances. It’s wise to calculate the tax outcome both ways. The tax software (Renta Web) can help compare scenarios like these by toggling between individual and joint to see which yields less tax.

Example 2: If you’re a single parent in practice (the other parent is not in the household at all), then doing a joint return with your kids is usually beneficial unless your income is very low. 

If you have very low income, you might pay little tax either way, but you won’t lose anything by filing jointly. On the other hand, if you have a high income, the child allowances and joint filing reduction become more valuable. Keep in mind that the €5,550 personal allowance is per taxpayer and does not increase with joint filing (joint filing doesn’t double allowances, except the special reductions). 

Joint vs. individual for a single parent is primarily about that €2,150 reduction and combining incomes.

Example 3: For divorced or separated parents, only the parent who has custody and includes the children in a joint return gets the single-parent reduction; the other parent will file individually. 

With shared custody, you two should decide who claims the children each year. One option is alternating joint returns year by year. When it’s not your turn to claim a joint return, you’ll file an individual return and typically claim half of each child’s allowance (since the child is also considered dependent on you even though you didn’t claim the joint status that year). This scenario can be complex, and you must be careful that both parents don’t claim the joint benefit in the same year as it’s not allowed.

In short, as an unmarried parent you can file individually or jointly (with your kids), but you cannot file a joint return with another adult unless you marry them. The decision on individual vs joint should be based on which results in less tax. 

Many tax filers use draft and simulation tools to compare both options. Remember that if you opt for a joint return one year, you’re not locked in permanently––you can switch back to an individual the next year if that makes sense, and vice versa. The tax law gives you this flexibility to ensure you’re not paying more tax than necessary given your family situation.

Special scenarios: custody, child support, and more

Every family situation is a little different, so we’ve outlined some special scenarios unmarried parents should keep in mind and how they affect your tax filings. The list isn’t exhaustive of every unique situation, but we believe it covers the bases for many individual families.

Joint custody arrangements: 

If you share custody of the children with the other parent (and you’re not married to each other), you both have equal rights to claim the child for tax purposes––just not at the same time. 

You might alternate years for joint filing, or simply each file individually and split allowances. The Spanish tax rules stipulate that in joint custody, either parent may claim the single-parent family unit (joint return) but then the other parent must file solo. From a practical standpoint, some divorced or separated parents agree that one parent always claims the children to get the tax reduction, especially if that parent has a significantly higher income or provides more financial support. Others alternate to share the benefit. 

There’s no one-size-fits-all answer; just ensure both parents don’t attempt to claim full dependent benefits for the same child in the same year, or it will raise a flag. Communication and perhaps a written agreement as part of your custody arrangement can help clarify this.

Sole custody: 

If you have sole custody of your child (the other parent is not involved in raising the child on a day-to-day basis), then you will generally include the child on your tax return every year. 

You qualify for the single-parent joint filing and all relevant deductions solely. The other parent, if they have no custody at all, usually cannot claim the child for any tax benefits. In cases where the non-custodial parent has visitation but pays child support, see the next scenario.

Child support (alimony for children): 

Child support payments (anualidades por alimentos por los hijos) have a specific tax treatment in Spain. 

If you are paying child support for your children to the other parent under a legal agreement or court order, those payments are deductible from your taxable income in the IRPF. Essentially, the payer gets to subtract the alimony amounts from the part of income taxed at the general scale. 

However, in exchange, the payer cannot claim the child’s tax-free allowance for those children. Instead, the law allows a different calculation where the personal allowance for the payer is adjusted (this gets a bit technical: the payer may still get a small allowance per child––roughly €1,980––but not the full dependent allowance, because you’re not maintaining the child fully). The parent receiving the child support does not have to include those payments as taxable income, as child support is tax-exempt for the recipient. 

But the recipient (custodial parent) also needs to be careful. If they are receiving child support, it means the children do have an independent source of support, which disqualifies the custodial parent from claiming the special €1,200 single-parent-of-two-kids credit (one of the conditions for that credit is that the kids not have the right to receive alimony from the other parent). The presence of court-ordered child support basically shifts the tax benefits: the paying parent gets a deduction for the payments, and the custodial parent still gets to claim the children for the basic allowances (and large family credit if applicable), but not the single-parent credit.

Unmarried couples living together: 

It’s worth re-emphasizing this scenario, as it’s common. If you are not married but cohabiting with your partner and you have children together, you are taxed as two separate individuals. 

You cannot file a combined joint return as a couple, and you do not get the married couple allowance or reduction. One of you can claim a joint return with the kids (taking all child allowances and the €2,150 single-parent reduction) only if the other partner agrees not to list the kids as dependents on their own return. In practice, if you are living together and sharing finances, splitting the child allowances between two individual returns might result in a better overall outcome than one parent taking everything. 

Why, though? Because each parent then enjoys a portion of the tax-free child allowance against their income. If instead one parent takes the full child allowance and the other parent claims nothing for the kids, the second parent might end up with a higher taxable income (since they can’t use any child allowance). On the flip side, the first parent gets the extra €2,150 reduction. You’d have to compare the tax savings as a family. Many cohabiting couples actually find it simplest to each claim their share (50/50) by default with individual returns. 

Remember: the law explicitly says if an unmarried couple lives together with children, they cannot both benefit from single-parent status..

Benefits for disabled dependents: 

If you have a child with a disability, there are additional allowances and credits (for example, a higher child allowance and a separate €1,200 credit for each dependent with a disability ≥33%). 

These apply regardless of marital status. Make sure to indicate the disability details on the tax form (including the official disability degree) to claim all applicable benefits. This might not apply to everyone, but it’s an important note for those to which it does––you could get a substantial reduction per disabled child or even an additional credit similar to the ones above.

As you can see, unmarried parents need to navigate a few extra wrinkles in tax filing. 

The good news is that Spain’s tax system ultimately provides similar relief for families whether or not the parents are married. It’s largely about allocating who claims what. If you’re ever unsure, don’t hesitate to seek professional advice or use tools (the Renta web portal allows you to simulate both individual and joint filings to compare outcomes). In complex cases like splitting deductions or handling alimony, expert guidance can ensure you don’t miss out on savings or accidentally misreport something.

How to optimize your return as an unmarried parent in Spain

Filing taxes as a Spain-based, unmarried parent may seem daunting, but with the right knowledge you can confidently navigate your Declaración de la Renta. Let’s recap:

• Make sure you determine your filing status correctly (individual vs joint) 
• … and include your children on your return if they qualify. 
• Take advantage of all the allowances for dependents 
• … and the deductions like the working parent credit or single-parent credits.
• Remember that you have options––you can choose how to file each year based on what benefits you the most.

If you’re feeling unsure about how to proceed or simply want to ensure you’re doing everything by the book while maximizing your deductions, you’re not alone. Tax laws can be complex, especially with personal family situations and changing regulations. This is where getting professional help can be invaluable. 

Xolo offers specialized tax services for individuals in Spain (particularly freelancers and expats) that can take the stress off your shoulders. With Xolo’s Spanish tax service, you’ll have expert accountants to guide you and even handle filing on your behalf. It’s our team’s job to advise you on the best filing option (joint or individual) for your living situation, manage your paperwork, and help you avoid costly mistakes.

File confidently with Xolo by your side , knowing localised professionals have optimized your return for you. Xolo is the support you need to make the most of the tax benefits available for you and your family.

Ready to simplify your tax filing? Let Xolo handle your Spanish income tax return. 

Learn more about Xolo’s tax solutions for Spain and get started now––so you can focus on your family, while we take care of your taxes.