Private and Family Loans in Spain: What Happens If the Money Is Never Repaid?

Can the Spanish Tax Agency treat an unpaid family loan as a hidden gift or unexplained taxable income? Could you face tax penalties of up to 150%? Recent Spanish court rulings highlight why the way private loans are documented can have serious financial consequences.

Lending money to your children, helping a relative buy a property in Spain, or receiving a substantial bank transfer from a family member may seem straightforward.

However, when money is transferred under a private loan agreement but never repaid, the Spanish tax authorities (Agencia Tributaria, commonly known as Hacienda) may question whether a genuine loan ever existed.

A November 2025 ruling by the High Court of Justice of Asturias examined transfers totalling €255,000 that taxpayers claimed were private loans. The court upheld the tax authorities' position after finding that the alleged loans had not been sufficiently substantiated.

But there is an essential distinction:

A genuine loan that remains unpaid does not automatically become a gift or unexplained capital gain.

The tax consequences depend on the true nature of the transaction and the evidence available to support it.

1. What happens if you lend money to a family member in Spain and they never repay it?

Loans between private individuals are legal in Spain, including loans between parents and children, siblings, partners, friends and unrelated individuals.

They may also be interest-free.

Problems arise when significant sums of money are transferred without adequate documentation, repayment arrangements are unclear, or many years pass without any repayments or credible explanation for the outstanding debt.

In these circumstances, the Spanish Tax Agency may investigate whether the money was genuinely lent or whether the loan agreement was intended to disguise a different transaction.

However, failure to repay a genuine loan is not, by itself, proof of a disguised gift.

A borrower may genuinely be unable to repay because of financial difficulties. The parties may agree to extend the repayment period, or the lender may pursue an outstanding debt.

These situations must not be confused with arrangements where there was never any real intention to repay the money.

Understanding the difference is essential.

2. Genuine loan, forgiven debt or fictitious loan: three very different tax consequences

This distinction is fundamental: being unable to repay money that was genuinely borrowed is not the same as receiving a gift disguised as a loan.

Nor can every unpaid family loan automatically be reclassified as a donation.

The tax authorities must examine the actual facts, supporting evidence and legal nature of the transaction.

Where the evidence establishes a genuine gift, that transaction must be assessed under the appropriate tax rules rather than indiscriminately treated as unexplained income.

3. A significant Spanish court ruling: €255,000 allegedly received as private loans

On 21 November 2025, the High Court of Justice of Asturias (Judgment 1026/2025) examined a dispute involving bank transfers totalling €255,000 received from a non-resident's bank account.

The taxpayers maintained that the transfers represented private loans.

However, the Spanish Tax Agency questioned whether genuine loan agreements existed.

Among the relevant circumstances were the lack of sufficiently persuasive contemporaneous evidence, the absence of conduct consistent with the claimed repayment arrangements and documentation introduced after the transactions.

The taxpayers argued that verbal loan agreements were legally valid and relied on subsequent acknowledgements of debt.

The court accepted that Spanish civil law does not generally require a loan agreement to be executed in a public deed.

However, a contract being legally possible without written documentation does not mean its existence has been proved for tax purposes.

The court upheld the challenged tax assessment and penalties.

The broader proceedings resulted in a tax assessment of €138,706.58 and penalties totalling €91,595.40. These figures related to the proceedings as a whole and should not be interpreted as an automatic calculation arising solely from the €255,000 in transfers.

Why does this judgment matter?

It illustrates a significant risk for anyone receiving substantial sums under informal loan arrangements.

A debt acknowledgement signed before a notary after a tax investigation has begun does not necessarily prove that a genuine loan existed when the money was originally transferred.

The circumstances surrounding the transfer, the original agreement and the parties' subsequent behaviour may all be relevant.

For international families, where large transfers between countries are relatively common, this is particularly important.

4. The Spanish Supreme Court clarifies what taxpayers must prove

A separate ruling by the Spanish Supreme Court, Judgment 1537/2025 of 27 November 2025, provides an important clarification concerning unexplained capital gains.

The Court established that, when taxpayers seek to challenge the classification of an asset or receipt as an unexplained capital gain, three essential matters must be demonstrated.

Where did the money come from?

The means by which the funds were transferred must be identifiable.

For example, a bank transfer may provide evidence of the movement of money.

Who provided the money?

The person who transferred the funds must be identifiable.

Why was the money transferred?

The legal basis of the transaction must be established.

Was it a loan, a gift, repayment of an existing debt or another genuine transaction?

This third question is particularly important.

A bank transfer can demonstrate that one person paid money to another. It does not, on its own, establish that the payment constituted a loan.

The Supreme Court also clarified an important limit on the powers of the tax authorities.

When the evidence sufficiently establishes the real legal nature of a transaction, the Administration must apply the tax treatment corresponding to that transaction.

It cannot automatically classify identifiable transfers as unexplained capital gains merely because it disagrees with their declared treatment.

The two judgments therefore highlight different aspects of the same principle: the evidence must support the transaction that the taxpayer claims actually occurred.

5. When can Hacienda treat a private loan as an unexplained capital gain?

Article 39 of Spain's Personal Income Tax Law (Ley del IRPF) regulates unexplained capital gains, known in Spanish as ganancias patrimoniales no justificadas.

These rules can apply where assets, rights or acquisitions are inconsistent with the taxpayer's declared income or wealth, subject to the statutory requirements.

In cases involving alleged private loans, the tax authorities may examine circumstances such as:

• Significant transfers with inadequate supporting documentation.

• Loan agreements without clear repayment conditions.

• Extended periods without repayment or demands for payment, with no credible explanation.

• Documents prepared only after a tax investigation begins.

• Debt acknowledgements that do not establish the underlying transaction.

• Inconsistencies between the claimed loan and the parties' actual behaviour.

None of these factors automatically proves fraud.

However, when considered together, they may influence how the transaction is classified for tax purposes.

If an unexplained capital gain is properly established under Article 39, it is generally included in the taxpayer's general taxable income base, potentially producing a substantial Spanish income tax liability.

The final tax treatment depends on the facts, applicable legislation and available evidence.

6. Spanish tax penalties: could you really be fined up to 150%?

Yes. In appropriate cases, the financial consequences of an incorrect tax declaration can extend beyond the additional tax due.

Article 191 of Spain's General Tax Law (Ley General Tributaria) regulates penalties for failing to pay tax that should have been included in a self-assessment.

The general penalty ranges are:

These percentages generally apply to the tax underpaid, not directly to the amount of money transferred.

Example: a tax adjustment following an investigation

Suppose a tax investigation results in an additional tax liability of €30,000.

These are illustrative figures. Late-payment interest may also apply, and the actual penalty depends on the legal classification and circumstances of the infringement.

Importantly, not every tax adjustment results in a penalty.

The Spanish Tax Agency must establish the relevant legal requirements, including taxpayer culpability, and justify the sanction imposed.

Statutory penalty reductions may also apply when the relevant conditions are satisfied.

7. Do family loans in Spain require Modelo 600?

Private loans are generally subject to, but exempt from, Transfer Tax under the Impuesto sobre Transmisiones Patrimoniales y Actos Jurídicos Documentados (ITP-AJD).

Consequently, Modelo 600 normally needs to be filed with the competent tax authority, even though the loan itself does not generate a Transfer Tax payment.

The exact filing requirements and deadlines depend on the applicable territorial rules and the circumstances of the transaction.

Filing Modelo 600 can help document the existence and date of the arrangement.

However, it is important to understand that filing a tax form does not, by itself, prove that the underlying loan is genuine.

The agreement and the parties' conduct must also support the declared transaction.

8. How to document a family loan properly in Spain

If you intend to lend a substantial amount of money to someone living in Spain, careful documentation from the outset can help prevent future disputes.

Prepare a written loan agreement

The agreement should identify the lender and borrower, the amount, repayment deadline, payment arrangements and whether interest is payable.

Keep clear banking records

Bank transfers should be traceable, and the transaction reference should identify the purpose of the payment.

File Modelo 600 where required

Check the relevant filing requirements, deadlines and exemption rules before completing the transaction.

Document repayments

Preserve bank statements and other evidence showing how and when the borrower repays the loan.

Record genuine changes to the agreement

If the parties agree to extend a repayment deadline or change the terms, the modification should be documented when it actually occurs.

Seek advice before forgiving the debt

If the lender later decides that repayment is no longer required, the cancellation of the debt may have Gift Tax consequences.

Good documentation is not simply about having a signed contract. It is about being able to demonstrate that the agreement reflects a real transaction.

9. Money transferred from Belgium, the UK or another country: does Spain tax foreign family loans?

International family loans deserve particular attention.

For example, a parent living in Belgium may lend money to a child who is resident in Spain to help purchase a property.

A British resident may transfer funds to a family member living in Andalucía.

Or a person may receive money from relatives in Germany, France or the Netherlands to finance a business or meet personal expenses.

Receiving money from a foreign bank account does not automatically make the transaction tax-free or exempt from scrutiny by the Spanish authorities.

The nature of the transaction remains decisive.

Relevant considerations may include:

• The tax residence of the lender and borrower.

• The purpose and amount of the transfer.

• Applicable Spanish and foreign tax legislation.

• Whether the arrangement is a genuine loan or gift.

• The evidence supporting the origin of the funds.

• Potential reporting, documentary and compliance obligations.

Where international estates, gifts or property purchases are involved, additional tax considerations may arise.

Obtaining professional advice before transferring large amounts can help avoid incorrect declarations and costly future disputes.

10. What should you do if the Spanish Tax Agency questions a private loan?

If you receive a letter or tax enquiry concerning money transferred by a family member or another private individual, it is important to review the facts before replying.

The first step is to identify the relevant bank transfers, reconstruct the source and purpose of the funds, examine any loan agreement and verify whether the subsequent conduct of the parties is consistent with the terms originally agreed.

It is not advisable to create retrospective documents that falsely suggest an agreement existed when it did not.

The appropriate response may differ considerably depending on whether the case concerns:

• A genuine unpaid loan.

• An authentic loan that was subsequently forgiven.

• A gift that was incorrectly reported as a loan.

• An inadequately documented transaction.

• A tax assessment based on an incorrect interpretation of the evidence.

An inaccurate or incomplete response to a Spanish tax enquiry can make the situation more difficult to resolve.

The most effective approach is to establish the facts, assess the relevant legislation and respond within the applicable deadline.

11. Professional tax advice on family loans, gifts and international transactions in Spain

At Cervantes Alarcón Consulting, we provide personalised Spanish tax advice to individuals, families, property owners, businesses and international clients.

Our services include assistance with:

• Private and family loan taxation.

• Gift and inheritance tax matters.

• Cross-border financial and property transactions.

• Spanish tax obligations for residents and non-residents.

• The tax implications of debt forgiveness.

• Tax enquiries, assessments and supporting documentation.

Based in the Garrucha, Mojácar and Vera area of Almería, we assist clients with tax matters involving Spain and other countries, coordinating with additional specialised professionals where necessary.

Have you lent or received a substantial amount of money?

Whether you are planning a family loan, considering forgiving a debt or responding to an enquiry from the Spanish Tax Agency, understanding the tax implications is essential.

Contact Cervantes Alarcón Consulting for personalised tax assistance in Spain.

Professional experience, individual attention and an international perspective.