A single legal or structural defect missed before completion can cost tens of thousands of euros after the keys change hands. In Spain, property defects — from undisclosed debts to illegal extensions — transfer automatically to the new owner at the moment of purchase. Due diligence is not an optional extra. It is the core of what we do.
At Paton & Mayr, we have developed a 12-point verification process that identifies every category of risk before our clients commit to anything.
Written by Carlos Paton, Real Estate Lawyer — Paton & Mayr | Updated: July 2026
What Is Real Estate Due Diligence in Spain?
Due diligence in a Spanish property transaction is the legal and administrative investigation carried out before the buyer signs any binding contract or pays any deposit beyond a minor reservation fee.
In the United States, the equivalent process — title search, inspection contingency, and closing attorney review — is well understood by most buyers. In Spain, the process covers the same core concerns but operates through different institutions: the Land Registry (Registro de la Propiedad), the Cadastre (Catastro), the local planning authority (Ayuntamiento), and the community of owners (Comunidad de Propietarios).
Critically, the Spanish notary does not conduct due diligence on your behalf. The notary authenticates the transaction — they verify that the seller has legal title at the moment of signing. They do not investigate debts, planning irregularities, or outstanding community charges. That is your lawyer's responsibility.
Why Due Diligence Is Different in Spain
Illegal constructions are widespread.
A significant proportion of properties in Spain — particularly on the Costa del Sol, Costa Blanca, and in rural areas — have some form of unauthorized construction. Extensions, pools, and outbuildings built without planning permission can be subject to demolition orders or fines that transfer to the new owner.
Debts follow the property, not the seller.
Mortgages, community charges, IBI arrears, and certain utility debts are linked to the property in Spain. A seller's outstanding debts do not disappear at completion — they become the buyer's problem unless verified and cleared beforehand.
The cadastral and registry records often conflict.
The Land Registry and the Cadastre are independent systems that frequently show different boundaries, sizes, and descriptions for the same property. These discrepancies must be identified and resolved before purchase.
Off-plan and new build purchases carry developer risk.
Pre-completion due diligence for new builds must include verification of the developer's financial standing, building licence, insurance, and bank guarantee.
Our 12-Point Due Diligence Checklist
Every property purchase handled by Paton & Mayr goes through the following verification process before we advise a client to sign any binding commitment.
Title Verification (Registro de la Propiedad)
We obtain a Nota Simple — the official Land Registry extract — confirming the seller's legal ownership, the property's registered description, and any charges, mortgages, or encumbrances recorded against it.
Debt and Mortgage Check
We verify that all mortgages, charges, and liens on the property will be cancelled at completion. Outstanding debts must be discharged before or at the notary signing.
Planning Permission & Illegal Constructions
We obtain a Certificado Urbanístico from the local authority confirming the property's planning status, verifying that all constructions are licensed, and checking whether any demolition or regularization orders are outstanding.
Community of Owners Charges
We request a certificate from the community administrator confirming the seller is up to date with all community fees (cuotas). Outstanding community charges become the buyer's liability at completion.
Cadastral Value vs Market Value
We compare the cadastral record (Catastro) with the Land Registry entry to identify discrepancies in size, boundaries, or description that could affect the purchase price, future taxes, or resale value.
Utility Bills and Service Contracts
We verify that all utility bills (electricity, water, gas) are current and that no arrears exist. We also review any service contracts (alarm systems, maintenance) that may transfer to the new owner.
Rental Licence Status
If the property is currently rented or is being purchased for rental purposes, we verify the tourist rental licence status and confirm compliance with current regional regulations.
Property Boundaries (Linderos)
We verify that the physical boundaries of the property match the Land Registry and cadastral descriptions, and identify any boundary disputes with neighboring properties.
Urban Planning Zoning
We confirm the property's zoning classification and check whether any urban development plans (PGOU or similar) could affect its use, value, or the land surrounding it.
Environmental Restrictions
We check whether the property or surrounding land falls within any protected zones (coastal protection, natural parks, flood zones) that restrict building, use, or future development.
Tax Implications (ITP/IVA, Plusvalía)
We calculate the applicable transfer tax or VAT, confirm the cadastral value for IBI purposes, and advise on the plusvalía municipal to ensure these are correctly handled at completion.
Contract Review and Negotiation
We review and negotiate the Contrato de Arras (reservation contract) and the final deed (Escritura Pública), ensuring all conditions, timelines, and protections are correctly documented before any money changes hands.
How Long Does Due Diligence Take in Spain?
A standard due diligence process for a residential resale property takes 1–3 weeks from instruction to completion of our report. Complex cases — rural properties, properties with planning irregularities, or transactions involving multiple ownership structures — may take longer.
We recommend beginning due diligence before signing the Contrato de Arras wherever possible, or negotiating a due diligence contingency into the arras to protect your deposit if issues are found.
Real Case: How Due Diligence Saved a US Buyer €50,000
One of our US clients was under offer on a property near Barcelona when our due diligence revealed an unauthorized extension covering 40% of the built area — constructed without planning permission and subject to a demolition order that the seller had not disclosed. The client withdrew without penalty. The cost of our due diligence: a fraction of the potential loss.
Read the full case study →Frequently Asked Questions
What is real estate due diligence in Spain?
Legal and administrative investigation before signing any contract. Covers title, debts, planning, community charges, and environmental restrictions. The Spanish notary does not perform this function — that is your lawyer's responsibility.
How much does due diligence cost in Spain?
Due diligence is included within the overall legal fee for the property transaction, which runs 1–1.5% of the purchase price. We provide a clear written fee estimate before engagement. No hidden costs.
Can I skip due diligence if the property looks straightforward?
No. The most costly problems — illegal constructions, undisclosed debts, planning irregularities — are rarely visible to the naked eye. A property can appear in perfect condition while carrying debts or demolition orders that transfer to the new owner at completion.
What happens if due diligence reveals a problem?
Depending on the nature and severity of the issue, options include: negotiating a price reduction, requiring the seller to rectify the problem before completion, withdrawing from the transaction with full deposit return, or proceeding with appropriate contractual protections.
Do I need due diligence for a new build in Spain?
Yes — but the focus is different. For new builds, due diligence covers the developer's financial standing, building licence, bank guarantee (aval bancario), and compliance with the purchase contract terms. Developer insolvency during construction is a real risk.
Can you conduct due diligence remotely for US buyers?
Yes. All our due diligence work is conducted in Spain on your behalf. You receive a written report in English covering all findings, risk assessment, and recommendations. No travel required.
Protect your investment before you sign anything.
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