Difference Between Complaint (“Denuncia”) & Criminal Complaint (“Querella”)

Difference between complaint (“denuncia”) and criminal complaint (“querella”)

When someone has suffered a crime or is aware that one has been committed, the first reaction is usually the same: I want to report it. But as soon as the matter is placed in the hands of a lawyer, a question arises that many people had not considered: is it better to file a denuncia or a querella? Aren’t they the same thing? What is the difference between the two? Which one is advisable in my case?

The denuncia and the querella are the two main mechanisms that the Spanish legal system makes available to citizens to set the machinery of criminal proceedings in motion. Both serve to inform the authorities of the existence of allegedly criminal acts, but their legal nature, their formal requirements, their procedural effects, and the consequences they have for the person who files them are radically different. Confusing them, or choosing the wrong one without advice, can make the difference between a process that reaches a successful outcome and one that is dismissed before it even begins.

In this article we explain in detail what a denuncia is, what a querella is, how they differ, when it is advisable to use each one, and what consequences the choice has for the person who seeks justice. A clear understanding of these two legal figures is the first step to acting effectively when a crime has been suffered.

What is a criminal complaint (denuncia)?

A criminal complaint (denuncia) is the communication made by a person —the victim, a witness, or any citizen— to the competent authorities —police, public prosecutor’s office, or court— to inform them of the existence of facts that could constitute a crime. It is the simplest and most accessible act that the legal system provides to citizens to activate criminal action.

The complaint can be filed orally or in writing and, in principle, does not require the assistance of a lawyer or a procurator. It may be submitted directly to the police —at any police station or Civil Guard post—, to the Public Prosecutor’s Office, or directly to the investigating court. Its format is relatively flexible: the essential thing is that it describes the facts as precisely as possible and identifies, if known, the person or persons responsible.

One of the most important characteristics of the denuncia —and what radically distinguishes it from the querella— is that the person who files it does not automatically become a party to the criminal proceedings. The complainant informs the authorities of the facts and, from that moment on, it is the State that assumes responsibility for investigating and, where appropriate, prosecuting. The complainant has no control over the development of the proceedings, cannot propose evidence or request investigative actions, and does not have the right to be notified of all decisions issued, unless they formally appear as a private prosecutor.

This feature has a very important practical consequence: if the court decides to dismiss the complaint for any reason —because the facts do not appear to constitute a crime, because the perpetrator cannot be identified, or because the evidence is insufficient— the complainant who has not appeared as a party may not even be aware of the dismissal and will have limited ability to appeal that decision.

Is there an obligation to report?

One of the issues that most surprises those unfamiliar with criminal law is that, in Spain, reporting a crime is in many cases a legal obligation, not simply an option. The Criminal Procedure Act establishes that any person who becomes aware of the commission of a public offense has the duty to inform the judicial authority or the Public Prosecutor’s Office.

However, this obligation has important exceptions. Close relatives of the alleged offender —spouse, ascendants, descendants, and relatives up to the second degree— are not obliged to report, nor are those who would have to testify against themselves. Nor are those who have learned of the facts in the exercise of certain professions subject to professional secrecy, such as lawyers with respect to matters entrusted to them by their clients.

The direct victim of the crime, however, not only has the right but also full freedom to decide whether or not to report, except in certain serious crimes —such as crimes against life or physical integrity— in which ex officio action by the prosecutor and the police means that the victim’s complaint is not essential for the process to begin.

What is a criminal complaint (querella)?

A criminal complaint (querella) is a much more formal and technical way of initiating criminal proceedings. Unlike the denuncia, the querella is not simply a communication of facts: it is a procedural act by which the person filing it directly exercises criminal action and becomes a prosecuting party in the proceedings.

The querella must necessarily be submitted in writing and requires the assistance of a lawyer and a procurator. It cannot be filed with the police or orally: it must be addressed directly to the competent investigating court and comply with a set of formal requirements expressly established by law. These include identification of the complainant, a detailed account of the facts, their provisional legal classification —that is, the criminal offense under which they fall—, a request for the investigative actions considered necessary, and, in most cases, the posting of a bond set by the judge.

The fundamental difference with the denuncia is that the person filing a querella becomes an active party in the criminal proceedings from the moment it is filed. This means they have the right to be notified of all decisions issued, can propose investigative measures, can appeal unfavorable decisions —including the decision to dismiss the case— and can prosecute during the trial with the same rights as the public prosecutor.

This active role in the proceedings makes the querella a much more powerful tool than the denuncia for those who want to ensure control over the development of the procedure and maximize the chances that the case will go to trial and end in a conviction.

Essential differences between denuncia and querella

Formal requirements
The denuncia is an informal act that can be made verbally or in writing, without legal representation and before any authority competent to receive it: police, Civil Guard, prosecutor’s office, or court. The querella, on the other hand, is a formal act that must always be submitted in writing, before the competent court, and signed by a lawyer and procurator. Its drafting requires technical precision and legal knowledge.

Position in the proceedings
The complainant does not acquire the status of a party in criminal proceedings merely by filing a denuncia. If they wish to participate actively, they must later appear as a private prosecutor, which involves hiring a lawyer and procurator. The querellante, by contrast, becomes a party from the moment the querella is filed: they already have legal representation, have exercised criminal action, and are formally part of the case from the outset.

Control over the proceedings
The complainant has little control once the complaint is filed: the State —through the judge and the prosecutor— leads the investigation. If the case is dismissed, a complainant who has not appeared as a party has very limited options. The querellante, however, maintains active control: they can propose investigative actions, appeal unfavorable rulings, and pursue the accusation even if the prosecutor decides not to.

The bond
One of the most practical differences is that the querella may require the posting of a financial bond set by the judge. This bond serves a dual purpose: to ensure that the complainant will cover legal costs if the querella is unfounded, and to discourage frivolous or bad-faith complaints. A denuncia, by contrast, requires no bond. This difference can be economically significant, especially when the accused has resources and could litigate to impose high costs on the complainant if they lose.

Obligation vs. voluntariness
Filing a denuncia may in some cases be a legal obligation, with consequences if not fulfilled. Filing a querella, however, is always voluntary: no one is obliged to do so, even if they have suffered a crime. It is a strategic decision that should be taken with legal advice, weighing costs, benefits, and chances of success.

When should you file a denuncia and when a querella?

The choice should not be automatic or based on what is quickest or simplest. It should result from a strategic analysis of the specific situation, with advice from a criminal lawyer familiar with the type of offense, the strength of available evidence, and the desired objectives.

When a denuncia is usually sufficient
In many cases, the denuncia is a natural and sufficient starting point. It is appropriate when the facts are clear and well documented, the perpetrator is identified, and there is enough evidence for the judge to open an investigation without additional steps, or when the police can act quickly and effectively from the outset.

It may also be preferable when the complainant does not yet have all the information needed to file a technically solid querella. In that case, the complaint activates the investigation while the lawyer studies the case, and if the court does not proceed diligently, the complainant can later appear as a private prosecutor.

When a querella is preferable
The querella is advisable when one wants to ensure active control from the beginning and the ability to appeal any unfavorable decision. It is especially recommended:

• When the facts are complex and require specific investigative actions.
• When there is a risk the court may dismiss the complaint without sufficient investigation.
• When the offense is serious and the victim wants full prosecutorial capacity.
• When one wants to maintain the accusation even if the prosecutor does not.
• When dealing with private offenses (e.g., defamation between individuals), where the querella is the only way to initiate proceedings.

Private offenses: when a querella is mandatory

In certain offenses, the law requires that criminal action be initiated exclusively through a querella. These are so-called private offenses, such as insults or defamation between private individuals without public relevance. In these cases, if the victim does not file a querella, the process cannot begin.

There are also semi-public offenses, where proceedings may begin ex officio but can be affected by the victim’s forgiveness or withdrawal.

The importance of prior legal advice

Choosing between denuncia and querella is one of the first and most important strategic decisions after a crime. A mistake at this stage can jeopardize the entire process: a complaint dismissed without appeal, or a poorly drafted querella rejected for formal defects, can mean lost time and a more difficult second attempt.

Therefore, it is essential to consult a specialized criminal lawyer who can assess the case, evaluate evidence, recommend the best course, and, if necessary, draft a technically sound querella.

An experienced criminal lawyer not only knows which option is best but also how to manage the case, propose effective investigative actions, appeal unfavorable decisions, and build a solid prosecutorial strategy.

Frequently asked questions

Can a denuncia become a querella?
Not exactly. There is no formal mechanism to convert one into the other. However, after filing a denuncia, the complainant can appear as a private prosecutor in the proceedings, effectively gaining similar control.

Can anyone file a querella?
In public offenses, any citizen may exercise criminal action (popular action), even if not directly affected. In semi-public and private offenses, this right is limited to the victim or authorized persons.

What happens if the querella is unfounded?
If dismissed or resulting in acquittal, and found to be baseless or in bad faith, the complainant may be ordered to pay costs and could face liability for false accusation.

Can a querella be withdrawn?
Yes, but with nuances. In private offenses, withdrawal may end the case. In public offenses, proceedings may continue regardless.

How much does a querella cost?
It includes lawyer and procurator fees plus any bond set by the court. Costs vary depending on complexity, but in serious cases with strong evidence, the investment is often justified by the procedural advantages.