Letter of Guarantee Spain (Carta de Garantía / Aval Personal)

A Letter of Guarantee Spain (Carta de Garantía or Aval Personal) is a written instrument by which a third party — the guarantor (fiador) — undertakes to the creditor (acreedor) that they will satisfy the debtor's (deudor's) obligation if the debtor fails to do so, pursuant to the legal framework of the fianza (suretyship) contract established in Articles 1822 through 1856 of the Código Civil (Real Decreto de 24 de julio de 1889). The Letter of Guarantee Spain is the personal guarantee (garantía personal) instrument most commonly used in Spain for rental agreements, commercial contracts, loan obligations, and business relationships where the creditor requires additional security beyond the debtor's own creditworthiness.

Article 1822 CC defines fianza as the contract by which a person binds themselves to pay or perform for a third party in the case that the third party does not do so themselves. The guarantor's obligation (obligación del fiador) is accessory (accesoria) to the principal obligation — it cannot exceed what the principal debtor owes, and it shares the same defences (excepciones) that the debtor has against the creditor under Article 1853 CC. The guarantee contract (contrato de fianza) requires the consent of the creditor and the guarantor — the principal debtor's consent is not legally required, though in practice it is typically informed and agreed.

Spain distinguishes between two types of fianza based on the guarantor's liability order: (1) fianza simple — where the guarantor has the beneficio de excusión (benefit of excussion) under Article 1830 CC, meaning the creditor must first exhaust legal remedies against the principal debtor's assets before claiming against the guarantor; and (2) fianza solidaria (aval solidario) — where the guarantor expressly waives the beneficio de excusión and accepts joint and several liability (responsabilidad solidaria) with the debtor under Article 1831 CC, allowing the creditor to claim directly against the guarantor without first pursuing the debtor. The Letter of Guarantee Spain is most frequently structured as fianza solidaria — particularly in commercial contexts, urban leases under Ley 29/1994 de Arrendamientos Urbanos, and bank lending.

Bank guarantees (avales bancarios) issued by financial institutions regulated by the Banco de España under Ley 10/2014 de Ordenación, Supervisión y Solvencia de Entidades de Crédito follow different rules and documentation standards from personal Letters of Guarantee — they are subject to UCP 600 (Uniform Customs and Practice for Documentary Credits) for international transactions and to specific Banco de España circular regulations for domestic ones. The Letter of Guarantee Spain template on forms-legal.com addresses personal guarantees (avales personales) between individuals and companies, not bank guarantees.

For real estate transactions, the Ley 29/1994 de Arrendamientos Urbanos (LAU) Article 36 recognizes the validity of personal guarantees (aval personal) as an additional security in rental agreements beyond the mandatory fianza deposit (depósito en metálico) — the personal guarantee supplements the fianza deposit and is commonly required by landlords for high-value rental properties or commercial leases. For mortgage lending, the Ley 5/2019 Reguladora de los Contratos de Crédito Inmobiliario requires specific pre-contractual disclosures and independent legal advice for guarantors of mortgage loans under certain conditions.

A Letter of Guarantee Spain is needed whenever a creditor requires additional personal security from a third party — beyond the debtor's own capacity — before extending credit, entering a lease, or completing a commercial transaction.

The document is required in residential and commercial lease agreements under Ley 29/1994 LAU when a landlord requires a personal guarantor (fiador personal) in addition to the mandatory fianza deposit — particularly common for foreign nationals, self-employed persons (autónomos), or tenants who cannot demonstrate sufficient regular income.

A Letter of Guarantee Spain is needed in commercial lending when a bank or private creditor extends a business loan (préstamo mercantil) to a Sociedad Limitada or autónomo and requires the company's administrator or a third party to provide personal guarantee (aval personal solidario) against the business's default — a practice regulated by the Banco de España and subject to CIRBE (Central de Información de Riesgos del Banco de España) reporting.

The document is required in supply contracts (contratos de suministro) between companies when the purchasing party's payment capacity is uncertain and the supplier requires a guarantee from a creditworthy third party — the parent company, a major shareholder, or an independent guarantor.

A Letter of Guarantee Spain is needed when a construction contractor (contratista) or subcontractor must provide a guarantee of performance (garantía de ejecución) or payment guarantee to the developer (promotor inmobiliario) under Ley 38/1999 de Ordenación de la Edificación (LOE) — particularly for contracts exceeding thresholds requiring formal guarantees.

The document is required when participating in public procurement (contratación pública) under Ley 9/2017 de Contratos del Sector Público (LCSP) — Article 107 LCSP requires provisional (garantía provisional) and definitive (garantía definitiva) guarantees from contractors bidding for public contracts, though these are typically bank guarantees rather than personal letters.

A Letter of Guarantee Spain is also needed in franchise agreements (contratos de franquicia) and distribution agreements (contratos de distribución) where the franchisor or manufacturer requires the franchisee or distributor to provide a personal guarantee of their obligations under the commercial agreement.

Parties in Spain should prepare a Letter of Guarantee Spain (Carta de Garantía / Aval Personal) proactively rather than waiting for a dispute to arise. Courts interpret agreements based on the written terms rather than oral representations. Under the Ley Cambiaria y del Cheque (Ley 19/1985), promissory notes and bills of exchange are governed in Spain. The Banco de España supervises banking under Ley 10/2014. The Comisión Nacional del Mercado de Valores (CNMV) regulates securities markets. The AEAT administers IVA (Ley 37/1992) and IRPF (Ley 35/2006). The Ley 3/2004 governs late payment in commercial transactions with statutory interest. Where the transaction involves regulated activities, prior approval from the relevant authority may be required before execution.

A valid Letter of Guarantee Spain under the Código Civil fianza provisions must contain the following essential elements to be legally enforceable and to clearly define the scope and limits of the guarantor's obligation.

Identification of All Three Parties: (1) The guarantor (fiador) — full name, DNI or NIE (for individuals) or NIF/CIF and registered address (for companies), capacity in which they act, and where acting for a company, their authority to bind it (cargo and poder notarial reference). (2) The creditor (acreedor) — full name, DNI/NIE/NIF, and address. (3) The principal debtor (deudor principal) — full name, DNI/NIE/NIF, and address. The triangular nature of the guarantee must be explicit — the guarantor commits to the creditor, in relation to the debtor's obligation.

Description of the Guaranteed Obligation: A precise description of the principal obligation being guaranteed — the underlying contract (contrato de arrendamiento, préstamo, compraventa, contrato de obra, etc.), the parties to it, the date, and the amount or maximum exposure guaranteed. Article 1823 CC requires that the guarantee be express (expresa) and must not be extended to more than the debtor owes. If the guarantee covers a periodic or variable obligation (such as rent under a lease), the maximum guaranteed amount or the guaranteed period must be specified.

Guarantee Amount and Cap: The maximum amount (importe máximo garantizado) for which the guarantor is liable. Spanish courts interpret guarantee caps strictly — the guarantor is not liable beyond the agreed cap even if the actual debt exceeds it. The cap should expressly include or exclude: principal (principal); interest (intereses ordinarios and intereses de demora under Código Civil Article 1108); enforcement costs (costas judiciales); and ancillary charges (gastos). Article 1827 CC provides that the guarantee cannot exceed the principal obligation nor be constituted on more burdensome conditions — any clause purporting to extend the guarantee beyond the principal obligation is reduced to the level of the principal obligation.

Type of Guarantee — Solidaria or Simple: An express statement of whether the guarantee is fianza solidaria (aval solidario) — waiving the beneficio de excusión and beneficio de división — or fianza simple. For fianza solidaria, Article 1831 CC requires an explicit and unambiguous waiver. Creditors (banks, landlords) almost invariably require solidaria guarantees.

Duration: The period during which the guarantee is valid — fixed term (plazo determinado) or open-ended (indefinida). For lease guarantees under LAU, the guarantee should mirror the duration of the lease and any extensions. Open-ended guarantees should specify conditions for termination by the guarantor — typically requiring written notice to the creditor and discharge of all existing guaranteed obligations.

Guarantor's Rights After Payment: Article 1839 CC grants the guarantor who pays the creditor the right of subrogation (subrogación) in the creditor's position and all their rights, actions, and securities against the principal debtor — including the right to claim the full amount paid plus interest. Article 1838 CC grants the guarantor the right of reimbursement (derecho de reembolso) against the debtor. These rights should be referenced in the guarantee to inform all parties.

Governing Law and Jurisdiction: The letter should specify that Spanish law governs (Código Civil, with applicable modifications from Ley 5/2019 for mortgage-related guarantees) and designate the courts of a specific jurisdiction (juzgados y tribunales del domicilio del acreedor or another agreed court) as the competent forum for disputes — subject to the rules of Article 50 of the Ley de Enjuiciamiento Civil (LEC) for personal jurisdiction.

Forms-legal.com provides this Letter of Guarantee Spain as a practical starting point. Personal guarantee obligations are financially significant — a guarantor should always seek independent legal advice from an abogado before signing, and should review their own financial exposure and the legal protections available under Spanish consumer protection law (Ley General para la Defensa de los Consumidores y Usuarios, RDL 1/2007) if they are acting as a consumer guarantor.

Under the Ley Cambiaria y del Cheque (Ley 19/1985), promissory notes and bills of exchange are governed in Spain. The Banco de España supervises banking under Ley 10/2014. The Comisión Nacional del Mercado de Valores (CNMV) regulates securities markets. The AEAT administers IVA (Ley 37/1992) and IRPF (Ley 35/2006). The Ley 3/2004 governs late payment in commercial transactions with statutory interest.