Complaint vs. Private Prosecution in Spain: Which Is Better?

Criminal proceedings can be started mainly in two ways: through a report (denuncia) or through a private prosecution (querella). Although they are often confused, they have very different procedural and economic implications.

The Report (Denuncia)

It is the act of informing the authorities (police, Civil Guard, court or prosecutor) of the existence of a presumably criminal act. It is a civic duty and does not require great formalities or the involvement of a lawyer or court agent.

The Private Prosecution (Querella)

The querella, by contrast, is a formal declaration of intent addressed to the competent investigating judge. By bringing one, you not only report the offence but join the proceedings as a private prosecutor from the outset, seeking the imposition of a penalty and, where applicable, civil liability.

The Practical Differences, One by One

• Form: the report can be filed verbally or in writing, with no special requirements. The private prosecution is a formal document with prescribed content (identification of the accused, account of the facts, investigative steps requested) and requires the involvement of a lawyer and a court agent.
• Position in the proceedings: once the report is filed, the reporting party stays outside the procedure: their later role will normally be that of a witness. The private prosecutor, by contrast, is a party to the proceedings from the start: they can propose investigative steps, take part in the examinations, appeal decisions they disagree with and influence the course of the investigation.
• Cost: the report requires no professionals and has no cost; the private prosecution involves lawyer and court agent fees, an investment that is justified when you want to drive the prosecution actively.
• Control of the outcome: someone who merely reports depends on the court and the public prosecutor pushing the case forward. Someone who brings a private prosecution does not need to wait: they sustain their own accusation.

What Happens After Filing

Once the report is filed, the court decides whether to open proceedings and carries out the first investigative steps; the reporting party will be summoned, normally as a witness, and informed of their rights. It is important to know that starting with a report closes no doors: the victim can later join the proceedings as a private prosecutor and from that moment acquire the same rights as a party.

The private prosecution, for its part, is filed before the competent investigating judge, who must rule on its admission. If admitted, the private prosecutor takes part in all proceedings from day one. If refused, that decision can be appealed.

Which One Suits Each Case

There is no universal answer, but there are clear criteria. The report is the natural route for flagrant or straightforward events — a robbery, an assault, a theft — where the initial police investigation needs no private impulse. The private prosecution pays off in complex matters, especially economic ones: fraud, unfair management or corporate disputes where the account requires an elaborate legal presentation and the investigation needs someone proposing specific steps and watching the deadlines.

There is also a widely used middle path: report immediately so no time is lost and, once proceedings are opened, join as a private prosecutor. This combines the speed of the report with the procedural control of the private prosecution.

Frequent Mistakes

• Believing that filing a report grants party status: without formally joining, the reporting party neither controls the proceedings nor can appeal.
• Waiting too long to join, letting stages of the investigation pass in which the private prosecution could have had influence.
• Using the private prosecution as a pressure tool in purely civil or commercial disputes: if the facts have no criminal relevance, refusal is the likely outcome.

In short, the choice between a report and a private prosecution is a strategic decision best taken with advice and with the whole procedure in view: what you want to achieve, what evidence already exists and what will have to be built, and what role the victim wants to play in the process. Choosing the right entry door saves months of processing and avoids mistakes that are hard to correct later.