Extraordinary expenses for children: what they are and how to manage them

The perennial confusion: what counts as an extraordinary expense and what doesn't

Few topics generate as much dispute between separated parents as extraordinary child expenses. Your daughter needs braces, your son wants to sign up for a summer camp, the paediatrician recommends a course of speech therapy. The bill arrives and the conflict begins: one parent pays, passes half the cost to the other, and the other refuses on the grounds that the expense was not extraordinary, or that they were never asked for their consent. The result is a string of tense messages that ultimately hurts the person least to blame: the children.

The root of the problem is that the line between an ordinary expense and an extraordinary one is not always clear. The law does not provide a closed list, and what one parent considers a necessary expense the other may see as an avoidable luxury. Add the emotional weight of a separation to that, and you have the perfect conditions for conflict.

But it can be managed well. The first step is to understand clearly what Spanish law and case law say. The second is to establish a system of communication and record-keeping that minimises disputes. And the third is to use tools that make the process transparent for both parties.

The key distinction is straightforward: ordinary expenses are predictable and recurring; extraordinary expenses are unpredictable, one-off, and not covered by child support. Within extraordinary expenses, however, there is a second fundamental distinction: those that are necessary and those that are not.

Ordinary vs extraordinary expenses: clear definitions and examples

To avoid misunderstandings, it helps to be clear about what belongs in each category. This is not a theoretical classification — it is the foundation on which financial responsibilities are divided between parents.

Ordinary expenses

These are predictable, recurring expenses necessary to cover a child's basic needs. They are normally covered by child support payments or, in shared custody arrangements, by whatever cost-sharing system has been agreed. They include:

• Food in both households.
• Housing: the child's proportional share of rent or mortgage.
• Clothing and footwear for each season.
• School supplies: textbooks, uniform, enrolment at the child's regular school.
• Healthcare covered by the Seguridad Social: paediatric appointments, scheduled vaccinations.
• Extracurricular activities the child was already doing before the separation and that are listed in the parenting agreement.
• Regular school transport.

The criterion is clear: if it is an expense you can anticipate and that recurs every month or every school year, it is ordinary.

Necessary extraordinary expenses

These are unpredictable but essential for the child's health or education. They do not require the prior consent of the other parent, because they respond to a genuine need. Both parents are obliged to contribute in the proportion set out in the agreement (normally 50/50). Common examples:

• Braces and dental treatment not covered by the Seguridad Social.
• Glasses and contact lenses prescribed by an ophthalmologist.
• Medical treatments not covered by insurance: physiotherapy, speech therapy for a diagnosed condition, prescribed psychological treatment.
• Surgical procedures not covered.
• Private tutoring when a learning difficulty has been documented by the school.
• Medications not funded by the Seguridad Social.

Non-necessary extraordinary expenses

These are expenses that, while beneficial for the child, do not respond to an essential need. They require prior agreement from both parents before being incurred. If one parent decides to cover the expense without consulting the other, they cannot demand that the other pay their share. Examples:

• Summer camps and school trips.
• New extracurricular activities: tennis lessons, horse riding, robotics.
• Private tutoring when there is no diagnosed learning difficulty.
• Special celebrations: first communions, birthday parties with entertainment.
• Technology: mobile phone, tablet, gaming console.
• Driving lessons when the child comes of age.
• Private university when a public alternative is available.

The line between necessary and non-necessary generates a great deal of conflict. Private maths tutoring may qualify as a necessary extraordinary expense if the child has a diagnosis of dyscalculia, but as a non-necessary extraordinary expense if they simply want to improve their grade. Context is everything.

What Spanish case law says

The Tribunal Supremo (Spain's Supreme Court) has built a consistent body of case law on extraordinary expenses that is worth knowing. The ruling of 15 October 2014 (STS 579/2014) established criteria that remain the standard reference:

• Extraordinary expenses are those that cannot be anticipated at the time child support is set, and that are not recurring.
• A distinction is drawn between necessary expenses (arising from the child's health or compulsory education) and voluntary expenses (optional, even if potentially beneficial).
• Necessary expenses do not require prior consent; voluntary ones do.
• Where there is no agreement on a voluntary expense, either parent may apply to the court for a decision.

Subsequent case law has refined this framework in specific situations. For example, the Tribunal Supremo ruling of 13 September 2017 held that extracurricular activities the child had been doing regularly before the separation are ordinary expenses, not extraordinary ones, because they are predictable. This is an important principle: if your child has been in English classes for three years, that expense is considered ordinary even if the parenting agreement does not mention it explicitly.

On the topic of shared child expenses after divorce, the Audiencias Provinciales (provincial appeal courts) have produced an extensive body of case law that, in general, insists on the need for parents to act in good faith and to prioritise the child's best interests over their own disputes.

One relevant point: where shared custody is in place, courts tend to split extraordinary expenses 50/50, unless there is a significant disparity in income between the parents. In sole custody arrangements, the split may vary according to the parenting agreement or court order, though a 50/50 division is also common even when child support covers the ordinary expenses.

How to manage extraordinary expenses without conflict

The key to avoiding disputes is not to eliminate extraordinary expenses, but to establish a clear system for handling them. The following steps will help reduce friction.

Document absolutely everything

Every extraordinary expense must have supporting documentation: invoice, receipt, medical prescription, school report. Without documentation, any claim becomes your word against the other parent's. Get into the habit of photographing every invoice and storing it in an organised way. If you use an app like Niddo, you can attach the receipt directly to the expense record so that both parents have access to the document, leaving no room for doubt.

Agree in advance whenever possible

For non-necessary extraordinary expenses, the rule is to consult before spending. But even for necessary ones, it is good practice to inform the other parent before incurring the expense, explaining the situation and providing the supporting documentation. A clear message along the lines of "The dentist recommends braces for Lucía — here is the quote and the report" is far more effective than passing on the bill after the fact.

In the parenting agreement, you can include specific clauses on how to request approval for extraordinary expenses: through which channel, within what response deadline, and what happens if there is no response within that deadline. The more detailed the agreement, the less room there is for interpretation.

Use digital tools for record-keeping and transparency

Screenshots of bank transfers and WhatsApp messages are a fragile and incomplete system. A well-organised record of child expenses requires categorisation, attached receipts, and automatic balance calculations. Digital tools designed for co-parenting offer exactly that: each parent logs their expenses, categorises them as ordinary or extraordinary, attaches the receipt, and the app calculates in real time what each party owes. Everything is stored in a searchable history that can also serve as documentary evidence in the event of a legal dispute.

Establish a protocol for emergencies

Not every extraordinary expense allows for prior consultation. If your child breaks an arm and needs an urgent X-ray at a private clinic because the public hospital has a long wait, you are not going to stop and negotiate at that moment. For situations like these, agree a protocol in advance: emergency medical expenses are initially covered by the parent who is with the child, communicated to the other within 24 hours, and then split according to the agreed arrangement.

Agree a clear protocol for emergencies: the parent present covers the expense, informs the other within 24 hours, and you settle the split afterwards. Your child's health cannot wait for a negotiation.

Common mistakes worth avoiding

Beyond good practices, there are mistakes that separated parents make frequently and that are worth keeping in mind:

• Enrolling the child in activities without consulting the other parent, then demanding payment. If there is no prior agreement for a non-necessary expense, you cannot require the other parent to cover their share.
• Refusing to pay a clearly necessary expense as a form of leverage. Beyond harming the child, this can have legal consequences. Courts take a dim view of a parent placing their personal dispute above the child's health or education.
• Failing to update financial agreements. Children's needs change over the years. What was a one-off extraordinary expense may become recurring — and therefore ordinary. Reviewing the parenting agreement and expense arrangements periodically prevents tensions from building up.
• Mixing personal expenses with child-related expenses. The taxi you took to bring the child to the doctor is a shareable expense. The coffee you had while you waited is not. Be rigorous to maintain your credibility. See our full list of mistakes when managing shared expenses to avoid the most common ones.

Start organising extraordinary expenses today

Managing extraordinary child expenses does not have to be a battleground. With a clear understanding of what the law says, an orderly communication system, and tools that provide transparency, it is entirely possible to divide these expenses fairly and without conflict.

The most important thing to remember is that behind every invoice there is a need your child has. Braces, glasses, tutoring, or a summer camp all contribute to their wellbeing and development. For a full picture of what these items add up to, you can consult our breakdown of the cost of raising a child in Spain. Handling those expenses with respect and good faith is a fundamental part of responsible co-parenting.

Download Niddo for free and start logging and sharing your children's expenses on a platform designed to give both parents complete visibility. When the finances are clear, conflict loses its foothold.