A notary friend gave me a figure that genuinely surprised me: 1 in 8 transactions gets stuck at the notary because of incomplete or incorrect documentation. Not fraud. Not lack of funds. Details that nobody spots until 48 hours before completion, when there is no time left to fix them.

The problem is simple: sellers, and many agents, don’t know which documents are critical. Or which of those documents have limited validity, or may not match what appears on the original title deed.

I’m going to explain what to check, when to do it, and why it matters.

The Passport and Identification: The Document That Doesn’t Always Match

If you are a foreign seller who bought years ago, your current passport is probably not the one you used for the purchase. Passport numbers change.

The notary needs to verify that you are the person who signed the original purchase. If the numbers don’t match, they cannot legally assume you are the same person. Even if it’s obvious.

You have three options. One of them takes time.

The first: bring the original passport, even if it expired back in 2010. If you still have it. Many people don’t.

The second: a renewal certificate from your government linking the old passport to the new one. Some countries issue it. Others don’t. Requesting it from abroad takes 2-4 weeks if your government is efficient.

The third, and the complicated one: an Identity Recognition Deed (Acta de Reconocimiento de Identidad) before a notary. You need two witnesses who know you personally. You go to the notary’s office before the sale, and they declare before the notary that you are the person who signed in 1995. The deed costs between 300 and 500 euros. It requires a prior appointment with the notary. You don’t do this 24 hours before completion. The notary’s diary is not open for this at short notice.

I saw a transaction paused for 72 hours waiting for the seller to bring documentation from France. Completion was postponed. The buyer nearly walked away. The seller panicked.

The lesson: if you bought more than 10 years ago and your identification has been renewed since, check this now. Don’t wait.

Incorrect Cadastral Reference: The One That Blocks Everything

The energy performance certificate is compulsory to sell. It is valid for 10 years. But there is a detail that almost nobody checks until the final week: the cadastral reference on that certificate doesn’t match the one in the Land Registry.

It sounds like a technicality. It isn’t. The notary needs to verify that the energy certificate corresponds to the property being sold. If it doesn’t match, the sale doesn’t proceed. It’s not delayed by two days. It is not authorised. Full stop.

This happens more often than it should:

Renovations that change the built size, but the Catastro (Spain’s cadastral registry) hasn’t been updated. Plot divisions that generate new references. Old administrative errors nobody had noticed.

The solution requires planning. Two or three months before completion, check the energy certificate and manually compare the cadastral reference against the Catastro. If there is a discrepancy, tell the seller immediately.

Correcting a cadastral reference is not a one-week procedure. It means an application to the administration, a potential inspection, and a new certificate. It takes 2-4 weeks with luck. Or it may simply be an error by the technician who issued the energy certificate, which can be corrected easily.

Incomplete Community Debt Certificate

You buy an apartment with a storage room and a parking space. They are separate properties with their own cadastral references.

The community debt certificate you requested covers the apartment, but not the storage room or the parking space. Technically correct if those properties are registered separately. But it creates a risk.

The buyer purchases all three, but the debt certificate doesn’t reflect that. If the community is owed four years of fees on those two properties, the liability follows the property. The buyer inherits it. Nobody knew.

This happens constantly, both in recently built properties and in older buildings. In the latter, it’s common to find parking spaces that were segregated many years after construction, obtaining their own independent cadastral reference in the process.

Solution: at least one month before completion, verify with the community of owners that they know every property being sold. Request a zero-debt certificate covering all the properties you are buying. If any of them doesn’t appear, ask for a written explanation of why. The absence of this certificate doesn’t automatically stop the sale, unless you accept to proceed with the purchase and take on a possible community debt of up to four years.

Expired Powers of Attorney

If the seller cannot attend the notary in person, they need a power of attorney. No exceptions.

But the power they signed five years ago has expired. Or it was specific to a purchase, not a sale.

The notary spots it during review. And refuses to proceed.

There is another problem almost nobody considers: if the seller has conflicting interests, for example, selling an inherited property while acting on behalf of other heirs, or representing several people with rights over the property, the power of attorney must explicitly include that condition. If the power doesn’t specify it, the notary refuses to proceed. A standard power does not cover representation of people with different interests, and using it without clarification can invalidate the transaction.

It happens rarely, but it happens. Sellers living outside Spain with old powers. Inheritances where the power covered the original purchase, not selling that purchase now. Changes in legal representation between planning the sale and reaching the notary. And especially in cases of multiple representation, or when there are heirs with partial rights.

Two months before completion, confirm that the seller holds a valid power of attorney. Either a general one, or one specifically for the sale of property. If they represent others or there is a conflict of interest, the power must state it in writing. If it doesn’t exist, they need a new one. A new power of attorney takes a week to arrange if the seller cooperates.

Expired Personal Documents: TIE, NIE, Residence Card…

The National Police issues the Foreigner Identity Number (NIE). It usually comes as a white or green paper document with a blue stamp. This NIE number is used to settle taxes (it is not the residence card). Sometimes this document carries an expiry date.

The owner doesn’t check it because they don’t use it. Then they want to sell. They arrive at the notary. The notary asks for it, and it turns out it hasn’t been valid for years.

The same happens with the residence card (often wrongly called the NIE, since it includes that number), or with the TIE card. Both expire, and renewing them takes time.

Solution: four months in advance, check which identification documents the seller holds. If any is expired or close to expiring, renew it before setting a completion date. The National Police takes 2-4 weeks for renewals.

Sometimes the notary accepts a Hacienda label, the proof that your NIE is registered with the tax administration as a taxpayer. That shows the NIE exists and is active, even if the physical document has expired. But don’t leave it to chance. Check with the notary what they will accept before setting the completion date.

The Checklist That Should Be Compulsory

Here is what almost never happens: a documentation review 8-10 weeks before completion, not two weeks.

• Seller’s passport or NIE. Exact number and validity date.
• Energy performance certificate. Cadastral reference manually verified against the Catastro.
• Community debt certificate. Every property included: apartment, garage, storage room, anything being sold.
• Power of attorney, if applicable. In force and valid for a sale.
• Cancellation documentation for any previous mortgage, if there is one.

If something is missing or doesn’t match, there is still time to fix it. Calmly. Without a 48-hour panic.

What to Do Now

If you are thinking of selling in the next six months, don’t wait until completion is in sight.

Gather your passport, NIE, and identity documentation. Check expiry dates. If there is a mortgage, make sure the cancellation documentation is ready. If there is a power of attorney, confirm it is valid.

Get the energy certificate if you don’t have one. Manually verify the cadastral reference against what appears in the Land Registry.

The community debt certificate should be requested in the month of the sale, not before. If signing takes place in the first week of the month, request the previous month’s certificate. That will clarify what debt exists up to that date. If there is outstanding debt, either it is paid before completion or the buyer takes it on. If you are selling multiple properties (apartment plus garage plus storage room), ask the community whether all the references can be unified in a single certificate. You save on cost and it simplifies the process.

When the serious offer arrives, you will pass the documentation review without surprises, and within 48 hours.