We prepare independent, technically sound economic, accounting and forensic expert reports, and we defend them in court.
Reviewed by Controlaudit's audit team · Firm registered with the ROAC under no. S1604 · Updated 13 October 2026
An economic expert report is a technical opinion that analyses facts with economic significance (balances, flows of money, results, values, damages) and explains them clearly to whoever has to decide: a judge, an arbitrator or the company itself. Its usefulness depends on two things: the technical rigour of the analysis and the expert's ability to defend it against questions and objections.
At Controlaudit we specialise in economic expert evidence and forensic accounting. Our team brings together experts in finance, accounting and auditing, and we work with professionals in technical fields such as cybersecurity, engineering or the environment when the matter requires it. We assist companies, law firms and courts in judicial and arbitration proceedings, insolvency and pre-insolvency processes, and in the prevention and investigation of fraud.
Forensic work goes a step further than accounting expertise: it reconstructs transactions, follows the money (cash tracing), identifies irregularities, and obtains and safeguards digital evidence so that it can be used in proceedings. We prepare fully defensible expert reports, economic and financial opinions, accounting verifications and economic valuations.
Civil proceedings. Art. 335 of the Spanish Civil Procedure Act (Ley de Enjuiciamiento Civil) allows the parties to submit expert reports where scientific, technical or practical knowledge is needed to assess relevant facts. When issuing the report, the expert must state, under oath or affirmation to tell the truth, that he or she has acted and will act with the greatest possible objectivity, taking into account both what may favour and what may harm any of the parties, and that he or she is aware of the criminal penalties that could be incurred for breach of that duty.
Party-appointed expert reports are submitted with the statement of claim or the defence (art. 336). If that is not possible, they must be announced in those pleadings and submitted as soon as they are available and, in any event, five days before the pre-trial hearing in ordinary proceedings or within thirty days of the statement of claim or defence in verbal proceedings (art. 337.1). The parties may also ask the court to appoint an expert (art. 339). Experts must hold the official qualification relevant to the subject matter and be recognised experts in it (art. 340).
At trial, the expert may be called to present or explain the report, answer questions and objections on method, premises and conclusions, and face criticism from the opposing expert (arts. 337.2 and 347). Party-appointed experts cannot be recused, but they can be challenged (tacha) on grounds such as kinship with the parties or an interest in the matter (arts. 124 and 343). The court weighs expert reports according to the rules of sound judgement (sana crítica) (art. 348).
Criminal proceedings. The Spanish Criminal Procedure Act (Ley de Enjuiciamiento Criminal) provides for expert reports during the investigation phase when scientific or artistic knowledge is required (arts. 456 et seq.) and for experts to give evidence at trial, where they answer questions and cross-examination from the parties (arts. 723 to 725).
Insolvency proceedings (concurso de acreedores). The Spanish Consolidated Insolvency Act (TRLC) gives rise to issues in which economic expert evidence is common, such as determining the date of insolvency, analysing transactions prior to the insolvency proceedings or the company's financial development.
| Situation | Rule | What it means |
|---|---|---|
| Party-appointed expert report in civil proceedings | Arts. 335 to 337 LEC | Oath of objectivity; submission with the statement of claim or defence or, if that is not possible, within the deadlines of art. 337. |
| Court-appointed expert | Arts. 339 and 346 LEC | Appointment at a party's request; written report and possible appearance at trial or hearing. |
| Expert requirements | Art. 340 LEC | Official qualification relevant to the subject matter and proven experience. |
| Appearance at trial | Arts. 347 and 348 LEC | Explanation, questions, objections and criticism from the opposing expert; assessment according to sound judgement. |
| Challenges to party-appointed experts | Arts. 124 and 343 LEC | Grounds such as kinship, interest in the matter or dependence on one of the parties. |
| Criminal proceedings | Arts. 456 et seq. and 723 to 725 LECrim | Expert report during the investigation and examination of experts at trial. |
Economic and accounting reports for civil, commercial and criminal proceedings and arbitrations: analysis of balances and movements, determination of results and equity, and contractual settlements.
Analysis of financial and equity developments, the date and causes of insolvency and transactions prior to the insolvency proceedings, as well as economic support in restructuring processes.
Detection and analysis of accounting irregularities, misappropriation, fictitious invoicing and conflicts of interest, with quantification of the loss and proposed control improvements.
Reconstructing the money trail through bank accounts, companies and third parties to identify where funds went and whether they can be recovered.
Obtaining, preserving and safeguarding electronic evidence (emails, accounting files, databases) with integrity guarantees, in collaboration with cybersecurity specialists.
Quantification of actual loss and loss of profit, price adjustments and warranties in company sales and purchases, and economic valuations for use in proceedings.
We study the matter, the subject of the expert report and the procedural deadlines, and check that there are no conflicts of interest or circumstances compromising our independence or objectivity.
We agree with the client and their lawyer the questions the report must answer, the documentation needed and the timetable for meeting the submission deadlines.
Review of the accounting records, bank documentation, contracts and digital evidence, with traceability of every piece of data used. The timeframe depends on the volume of information.
Written report setting out the purpose, sources, methodology, analysis and conclusions, together with the statement of objectivity required by law.
Preparation and appearance at the trial, hearing or arbitration hearing to explain the report and answer questions from the parties and the court.
It is a report prepared by an expert in accounting, finance or auditing that analyses facts with economic significance and quantifies amounts so that the judge or arbitrator can assess them. In civil proceedings it is governed by arts. 335 et seq. of the Spanish Civil Procedure Act.
As a general rule, with the statement of claim or the defence. If that is not possible, it must be announced in those pleadings and submitted as soon as it is available and, in any event, five days before the pre-trial hearing in ordinary proceedings or within thirty days of the statement of claim or defence in verbal proceedings (art. 337.1 LEC).
Although engaged by one of the parties, the expert is required by law to declare under oath or affirmation that he or she is acting with the greatest possible objectivity, taking into account what favours and what harms each party (art. 335.2 LEC). In addition, the expert can be challenged if he or she has an interest in the matter or a relationship with the parties. A biased report loses credibility before the court.
It is the expert’s appearance at the trial or hearing to confirm the report, explain it and answer questions and objections from the parties and the court. The Spanish Civil Procedure Act governs this appearance in arts. 337.2 and 347.
It means following the money trail: movements of funds between accounts, companies and individuals are reconstructed to identify where they came from and where they went. It is common in fraud investigations, corporate disputes and insolvency proceedings.
It is an estimate of the profit that was not earned as a result of the harmful event, comparing the actual situation with the one that would have existed without it. It requires historical data, reasonable assumptions and the deduction of costs that were not in fact incurred.
Before accepting any expert witness engagement, we analyse potential conflicts of interest and the independence requirements of audit legislation. If there is a conflict or a ground for challenge, we will not accept the engagement.
Yes. We take on engagements throughout Spain, appearing in person or, where the court so decides, by videoconference.
Legislation cited on this page, linked to its official text:
General information updated on 13/10/2026. It is not a substitute for an analysis of your specific case.
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