The purchase option (opcion de compra) in Spanish property: how option contracts work under Article 1255 of the Codigo Civil

A purchase option (opcion de compra) in Spain is an atypical contract under which a property owner grants a buyer the exclusive right, but not the obligation, to purchase a specific property at a fixed price within a set period. The Spanish Codigo Civil contains no dedicated article regulating it, so the option exists by virtue of Article 1255, the freedom of contract provision, which lets parties establish the clauses and conditions they consider convenient provided they are not contrary to law, morality or public order. This sets it apart from the arras deposit and from pre-emption rights, which are both governed by specific statutory provisions.

What is the legal basis for the opcion de compra?

The opcion de compra is what Spanish legal doctrine calls a negocio juridico atipico: a contract with no express regulation in the Codigo Civil. It does not sit under Article 1453, which governs sales on approval (venta a calidad de ensayo o prueba), nor under any specific article of the sale chapter. Its legal foundation is Article 1255, which states that contractors may establish the pacts, clauses and conditions they consider convenient, always provided they are not contrary to the laws, morality or public order.

The Tribunal Supremo has defined the option consistently across decades of jurisprudence. In its settled doctrine, the option grants the optante the exclusive faculty to give consent within a contractually fixed period to an offer of sale that is binding on the concedente, who cannot withdraw it during that period. Once the option is exercised, it is extinguished and the compraventa is automatically perfected, without the concedente being able to do anything to frustrate it. The Tribunal Supremo has explicitly held that the option is not assimilable to a compraventa: the option is a precontract, the sale is a contract. The difference is one of concept and nature (TS Sentencia 878/2011, 25 November 2011).

The future sale that the option projects must determine two things: the thing (the property) and the price, plus any matter necessary to complete the future contract. The concedente is bound from the moment the option is granted, even before exercise, by the obligation not to dispose of the property and to maintain the offer for the agreed period.

How does the opcion de compra differ from arras and pre-emption rights?

These three mechanisms are often confused but serve different functions in Spanish property transactions. The table below sets out the distinctions.

Feature	Opcion de compra	Arras (deposit)	Retracto (pre-emption)
Legal basis	CC Art 1255 (atypical)	CC Art 1454	CC Arts 1522-1542c
Nature	Precontract: right to decide whether to buy	Deposit on an agreed sale	Right to step into a completed sale to a third party
When it arises	Before any sale is agreed	When a sale is agreed but not completed	After a sale to a third party has occurred
Premium	Option premium paid for the right itself	Deposit counted toward the price	No premium; reimbursement of the sale price
Exercise	Optante decides within the period	Either party may withdraw with penalty	Pre-emption holder must match the third-party price
Registration	RH Art 14 (4-year max)	Not separately registrable	Registered via the sale it replaces

The arras reservation contract is a deposit on a sale already agreed between the parties. The pre-emption rights mechanism (retracto) is a right of first refusal that activates only after the owner has sold to a third party. The opcion de compra is different from both: it gives the buyer time to decide whether to commit at all, at a price fixed now, in exchange for a premium paid for the right itself.

What must an option contract contain to be registrable?

Registration in the Land Registry is what converts the option from a personal right between the parties into a real right enforceable against third parties. Without registration, a subsequent sale to a good faith buyer may leave the optante with only a damages claim, not recovery of the property.

The registration requirements are set out in Article 14 of the Reglamento Hipotecario (the mortgage regulations), which implements Article 2 of the Ley Hipotecaria. Three conditions must be met:

1. Express agreement to register. The parties must expressly agree that the option will be entered in the Land Registry. Registration is not automatic.
2. Stipulated price. The contract must state the price agreed for the acquisition of the property and, where applicable, the premium paid for granting the option.
3. Exercise period not exceeding four years. The period for exercising the option may not exceed four years from the date of registration. The parties may agree any shorter period within that maximum.

There is one special case. For a lease combined with an option to purchase, the law admits that the option period may extend for the full duration of the lease, but it necessarily expires if the lease is renewed on a tacit or legal basis. This exception reflects the common practice of combining a rental with a purchase right, which the property purchase contract guide covers from the sale side.

The Direccion General de Seguridad Juridica y Fe Publica confirmed these requirements in its Resolution of 10 April 2025 (BOE-A-2025-10050), adding an important clarification: an option that is in reality a disguised financing or guarantee mechanism, where the seller receives nearly the full price upfront and retains a right to terminate by repaying a larger sum, is not registrable. The registration system protects genuine purchase options, not transactions that function as secured loans without the consumer protections that mortgage law provides.

How does the exercise of the option work?

The exercise of the option is unilateral on the part of the optante. According to the settled doctrine of the Tribunal Supremo, it is sufficient for the optante to communicate the decision to exercise the right within the agreed period. Once that communication is made, the compraventa is perfected automatically. The concedente cannot refuse to complete, cannot impose new conditions, and cannot frustrate the sale.

This automatic perfection is the key operational feature. The option is a precontract that, once exercised, converts itself into the definitive sale contract without any further agreement needed. The property transfer method comparison covers how this sits alongside other transfer routes.

If the option is not exercised within the period, it simply expires. The premium paid for the option is not recoverable. The concedente has already been taxed on the premium when it was received, regardless of whether the sale ever takes place.

How is the option premium taxed?

The tax treatment of the opcion de compra has three stages: the grant of the option, the exercise (or non-exercise), and the treatment of the premium itself.

At the grant of the option:

When the concedente is a private individual acting outside any business activity, the premium constitutes a capital gain that must be declared in their IRPF (income tax). When the concedente acts within a business or professional activity, the premium is treated as business income, declared in IRPF or corporate tax as applicable.

For the optante, the tax depends on who grants the option. If the concedente is a business or professional, the premium is subject to IVA (VAT) at the general rate of 21 per cent. If the concedente is a private individual, the optante must pay ITP (Impuesto sobre Transmisiones Patrimoniales, the transfer tax) on the Onerosas modality. In this case, the tax authority presumes a minimum tax base of 5 per cent of the price agreed for the future sale, regardless of whether the parties agreed a lower premium or no premium at all.

At exercise of the option:

When the option is exercised, the transaction is taxed as an ordinary sale. For a resale from a private seller, the buyer pays ITP, which in Andalusia is a flat 7 per cent. For a new build from a developer, the buyer pays IVA at 10 per cent plus AJD at approximately 1.2 per cent. If the premium was initially deducted from the final price, that portion has already been taxed under its original concept and is not double-taxed.

If the option is not exercised:

The concedente has already declared the premium. For the optante, the lost premium may generate a capital loss in their IRPF if they acted as a private individual. If the option was linked to a business activity, the premium may be treated as a deductible expense.

The AEAT provides guidance on whether a property purchase attracts IVA or ITP, confirming that the same rules that apply to an ordinary sale apply when an option is exercised.

What are the risks of an unregistered option?

An unregistered option binds the concedente personally but does not bind third parties. If the concedente sells the property to a third party who registers the purchase in good faith before the option is exercised, the optante may lose the ability to recover the property and be left with a claim for damages against the concedente.

Registration under Article 14 of the Reglamento Hipotecario prevents this outcome. A registered option appears on the property’s registry entry, so any subsequent buyer is deemed to know of it. If the option is later exercised, the optante’s right prevails over the later acquisition.

The four-year maximum on the registered exercise period is a deliberate constraint. It prevents a property from being indefinitely tied up by an option that may never be exercised. Parties who need a longer period must use a different structure, such as a lease with an option (where the option runs for the lease term) or a conditional sale.

How does a lease with an option to purchase work?

The combination of a lease with an option to purchase (arrendamiento con opcion de compra) is common in Spain. The tenant rents the property and simultaneously acquires the right to buy it at a fixed price within a set period. The lease portion is governed by the LAU (Ley de Arrendamientos Urbanos), while the option portion depends on what the parties agree under Article 1255.

A frequent arrangement is that all or part of the rent paid during the lease is deducted from the final purchase price if the option is exercised. This is valid but must be expressly agreed. It is also valid, though less common, for the rent not to be deducted, or for a separate option premium to be charged alongside the rent.

For registration, the special rule applies: the option period may run for the full lease term, but it expires on any tacit or legal renewal of the lease. This prevents the option from running indefinitely through lease extensions that the parties did not expressly negotiate.

What should a foreign buyer know before signing an option?

Foreign buyers considering an opcion de compra should pay attention to four points.

First, the option is an atypical contract, so the parties have wide freedom to set the terms, but this also means there is no statutory safety net. Every material term, including the exercise period, the price, the premium, and whether the premium is refundable, must be written explicitly. Vague terms will be interpreted against the party who drafted them.

Second, registration is essential if the buyer wants protection against a subsequent sale to a third party. An unregistered option is a personal promise, not a property right.

Third, the tax treatment differs depending on whether the seller is a private individual or a business, and the optante may face an ITP liability on a presumed minimum base even if the premium is small. The guide to buying property in Spain as a foreigner covers the broader purchase process.

Fourth, the distinction between a genuine option and a disguised financing arrangement matters. The Direccion General has made clear that an option that functions as a secured loan, where the seller receives nearly the full price upfront and can terminate by repaying a larger sum, will not be registered. Buyers and sellers who want that structure should use a mortgage, which carries the consumer protections that the mortgage law framework provides.

This guide is general information, not legal or tax advice. Rules change and individual circumstances differ. Verify current requirements with an independent lawyer (abogado) or tax advisor (gestor/asesor fiscal) before acting.