Spain's Organic Law 1/2025 of 2 January, on measures to enhance the efficiency of the Public Justice Service — published in the Official Gazette on 3 January 2025 and in force from 3 April 2025 — has introduced the most significant change to Spanish civil procedure since the Civil Procedure Act of 2000: the mandatory attempt of an Appropriate Dispute Resolution Mechanism (MASC — Medio Adecuado de Solución de Controversias) as a prerequisite for filing any declaratory civil or commercial claim.
The MASC: Concept and Rationale
The MASC is not a specific form of alternative dispute resolution but an umbrella legal concept covering various routes: mediation, conciliation, lawyer-assisted negotiation (collaborative law), neutral expert opinion or other extrajudicial dispute resolution procedures. The law does not compel the parties to reach an agreement — that would violate the constitutional right of access to justice — but requires them to attempt the extrajudicial route in good faith before resorting to the courts.
The reform’s underlying rationale is the overload of the Spanish judicial system: more than three million civil matters filed annually, with average first-instance proceedings exceeding eighteen months in major cities. The legislature aims for a significant share of business and civil disputes to be resolved outside the courts — at lower cost, greater speed and with better preservation of the parties’ relationships.
Scope: Which Disputes Require a Prior MASC Attempt
The obligation covers civil and commercial declaratory proceedings, including ordinary and abbreviated (verbal) proceedings. Excluded are:
- Family proceedings involving minors (unless the court determines otherwise)
- Payment order proceedings (proceso monitorio) and bill-of-exchange proceedings
- Mortgage and non-mortgage enforcement
- Insolvency proceedings
- Voluntary jurisdiction proceedings
- Proceedings concerning fundamental rights
- Proceedings on civil status and capacity
The most significant exclusion for businesses is the payment order proceeding (proceso monitorio): claims for liquid monetary debts supported by documentation — unpaid invoices, matured loans — do not require a prior MASC. This covers the bulk of routine inter-company debt collection.
The MASC Certificate: Admissibility Requirement
The MASC certificate evidences that the parties have attempted the extrajudicial mechanism. Filing it alongside the claim is an admissibility requirement: without it, the court will refuse to admit the claim. The certificate may evidence two situations:
- Failed attempt: the requested party did not appear or appeared but no agreement was reached. Immediately enables filing of the claim.
- Partial agreement: agreement was reached on some issues but not all. Enables filing on the unresolved issues.
The certificate is issued by the mediator or institution that managed the MASC. There is no single official template, but it must include: identification of the parties, subject matter of the dispute, start and end dates of the procedure, and reason for conclusion without agreement.
The MASC Mediation Process Step by Step
Start request: either party may initiate the MASC. In commercial disputes, the prospective claimant typically does so. The request is filed with the chosen mediator or institution and must identify the parties, the subject matter and the approximate monetary value.
Summons and informational session: the mediator summons both parties within five working days. The session explains the procedure, fees and confidentiality rules. Each party is free to decide whether to proceed with mediation.
Mediation sessions: if both parties agree, sessions are held as needed. The mediator does not impose solutions but facilitates communication and helps the parties identify interests and agreement options. Proceedings are confidential: statements made during mediation cannot be used as evidence in subsequent judicial proceedings (Art. 9, Mediation Act 5/2012).
Conclusion: mediation concludes with full agreement, partial agreement or no agreement. The mediator issues the MASC certificate in any case.
MASC Costs vs. Litigation
| Item | MASC (private mediation) | Ordinary civil proceedings |
|---|---|---|
| Average duration | 4-8 weeks | 18-36 months (first instance) |
| Indicative cost | 500-3,000 € per party | 8,000-30,000 € per party |
| Confidentiality | Yes, legally protected | No (public proceedings) |
| Relationship preservation | High | Low |
| Control over outcome | High (own agreement) | Low (judge decides) |
Bar associations in major cities and chambers of commerce offer institutional mediation at reduced rates, particularly accessible to SMEs.
Impact on Corporate Litigation Strategy
The MASC obligation transforms how businesses manage disputes. Companies should incorporate MASC into their litigation management protocols: identify which conflicts are genuine mediation candidates — not merely formal compliance exercises — and retain relationships with mediators specialised in their sector for each type of dispute.
Unjustified refusal to engage with the MASC — or bad-faith participation with no genuine intention to negotiate — carries cost consequences: courts may impose costs on a party that refused the extrajudicial route without justification and ultimately loses the case. This is a powerful incentive for MASC to be treated as a genuine resolution opportunity rather than a procedural formality.
Selecting Accredited Mediators for Commercial Disputes
For complex commercial disputes, mediator selection is critical. A mediator with legal training and sector experience in the relevant dispute type — M&A, intellectual property, distribution, senior executive employment — can facilitate agreements that a generalist mediator could not. The Ministry of Justice’s Register of Mediators allows searching by speciality and location.
Accredited mediation institutions — such as the ICAM Mediation Service (Madrid Bar Association) or chamber of commerce mediation centres — offer additional quality guarantees, professional indemnity insurance and standardised administrative procedures that reduce the risk of formal challenge to the MASC certificate.
Strategic Considerations for Foreign Companies in Spain
Foreign companies with operations or counterparties in Spain should update their standard contract templates to include mediation clauses nominating a specific accredited institution for MASC purposes. This avoids disputes about which mediator or institution to use, accelerates the process and may allow selection of mediators with bilingual capacity. Existing contracts governed by Spanish law should also be reviewed for dispute resolution clauses, as the MASC obligation applies regardless of what the contract says — parties cannot contractually opt out of the pre-litigation attempt requirement.
