Your mother made a will with dementia: annulling it
Last updated 2026-09-01 · Reviewed by Jaime Piñeira Pardo, registered with the ICAM bar, no. 138826
The short answer
Sue for annulment of the will. Article 663.2 of the Código Civil bars from making a will anyone who at that moment cannot form or express their wishes even with support, and article 666 requires regard to be had only to the testator's state when the will was made. You sue before the sección civil del Tribunal de Instancia, with four years to do so and a retrospective medical report.
Your mother had been diagnosed with Alzheimer's three years earlier, did not recognise her grandchildren and had twice been admitted to hospital for disorientation. In March, accompanied by your sister, she made a new will leaving the flat to that sister and you only the strict legítima. There was an earlier will, made eight years ago, dividing everything in halves. Your sister tells you the notary found her perfectly well and that the deed records that she had capacity. Your mother died in August.
The case, in five lines
- What is brought
- Action to annul the will for lack of capacity of the testator at the moment it was made, with an alternative request that the earlier will recover its effect.
- Before which court
- The sección civil del Tribunal de Instancia (the civil section of the first-instance court) of the deceased's last domicile, through ordinary proceedings given the usual value at stake and the need for expert evidence.
- Deadline
- Four years, a period case law takes from article 1301 of the Código Civil and which in practice is counted from the opening of the succession. It is a lapse period and is not interrupted by formal demands or family negotiations.
- Who can bring it
- Anyone harmed by the challenged will who would benefit from its annulment: forced heirs, heirs named in an earlier will and their successors.
- Financial risk
- The medical report is paid up front by whoever proposes it and is not always conclusive where the medical records are thin. If the case is lost, costs may be awarded against you and the challenged will is carried out as it stands.
Capacity is judged at a single instant, not over a stage of life
Article 666 of the Código Civil is categorical: in assessing the testator's capacity, regard shall be had only to the state she was in at the time the will was made. It is not enough to prove that your mother had a degenerative illness, nor that months later she was worse. The evidence has to be taken to the specific morning of that signing, and that shift is what makes the case difficult and what shapes its whole strategy.
Article 664 reinforces that logic from the other side by declaring valid a will made before mental incapacity set in. The law protects what was made while lucidity lasted and resists dragging a later deterioration backwards. That is why the case is won or lost by pinning down dates: when the decline began, what the doctors recorded that month, and what happened in the weeks before and after the deed.
A dementia diagnosis does not by itself prevent making a will
The starting point is article 662: everyone may make a will unless the law expressly forbids it. The prohibition is in article 663, which bars from making a will anyone under fourteen and anyone who at the moment of making it cannot form or express their wishes even with the help of aids or support. The key phrase is that last one: even with support.
Article 665 completes the picture: a person with a disability may make a will when, in the Notary's judgment, they can understand and express the scope of their provisions, and the Notary shall seek to have them develop their own decision-making process, supporting their understanding and reasoning and enabling them, with whatever adjustments are needed, to express their wishes, desires and preferences. The law favours the person being able to make a will, not the opposite.
The practical consequence is that the claim cannot limit itself to producing the Alzheimer's report. It has to show that the deterioration had reached the threshold of article 663.2 on that day, that is, that not even with support could she form or express a testamentary wish. That is a high bar and it is worth measuring coldly before deciding whether to litigate or to negotiate with the other side.
The notary's assessment under article 685 is the wall to bring down
Article 685 requires the Notary to know the testator, to identify her with two witnesses or with official documents if he does not know her, and to satisfy himself that, in his judgment, she has the legal capacity needed to make a will. That assessment is written into the deed and is the first obstacle in the case: the other side will hold it up as proof that your mother was fine, because a public professional saw her and put it on record.
That assessment, however, yields to evidence to the contrary. It is given in a short interview, without medical records to hand and with a type of deterioration that preserves social conversation for a long time. People with moderate dementia keep up polite formulas and answer closed questions well, so a twenty minute encounter does not detect what a structured cognitive examination does reveal.
That is why the work does not consist of attacking the notary, but of showing that on that day there were objective facts he could not know about. The thinner the record of capacity in the deed, and the richer the medical documentation from the surrounding weeks, the narrower the distance becomes between what was recorded and what was actually happening.
The retrospective report is built from medical records, not from opinions
The expert never examined the testator, so his report is worth as much as the material he works from. The central piece is the complete medical record from primary care, neurology and emergency services, with the notes from the consultations close to the date of the will. Dated cognitive test results, hospital discharge reports and treatment prescriptions are what make it possible to place the stage of the illness.
Around that base are placed verifiable facts from the surroundings: the dependency or disability assessment if one was applied for, the care home reports, and above all the financial conduct of those months. Unusual withdrawals, changes of account holders or repeated calls to the bank sketch a state that no isolated report explains on its own and that the court does weigh as a whole.
Taking money under the will you want annulled is the worst move
While the case is being studied, the other side usually offers to pay the legítima or to sign a quick division. Accepting without an express reservation of the annulment claim is exactly what their defence needs: you would be voluntarily carrying out the very will you later ask to have annulled, and that conduct of your own weighs in the court's final assessment.
The rule is the same as in any succession challenge: nothing is signed, and if sums have to be received it is recorded in writing that they are received on account and without waiver. And above all the calendar is watched, because the four years of article 1301 are a lapse period and do not stop while proposals are exchanged between siblings.
How we run the case, step by step
- 1
Fix the two dates that decide the case
We obtain the certificate of last wills and authorised copies of both wills, so as to place precisely the date of the challenged will and to check what would revive if the annulment succeeds.
- 2
Gather the complete medical record
We request the primary care, neurology, emergency and admission records, together with dated cognitive tests and prescriptions. This is the material without which no retrospective expert report holds up before the court.
- 3
Commission the retrospective medical report
A specialist analyses the stage of the illness on the exact date of the will and assesses whether the testator could understand and express the scope of her provisions, which is the threshold in articles 663 and 665.
- 4
Document the surroundings and the financial conduct
We identify carers, neighbours and health staff as witnesses and request the bank statements for the surrounding months, which show disposals and changes that reinforce or contradict the state described in the deed.
- 5
Sue for annulment and ask for the earlier will to revive
The claim is filed before the sección civil del Tribunal de Instancia within the four year period, seeks annulment for lack of capacity and, joined to it, a declaration that the earlier will is effective.
- 6
Hearing, judgment and division under the will that revives
At the hearing the expert, the notary and the witnesses give evidence. Once the judgment is final, the estate is divided under the earlier will, and if the co-heirs will not sign, judicial division of the estate is used.
The evidence that decides the case
- The complete medical record with the notes from the weeks before and after the will was made.
- Dated cognitive test results and the discharge reports from hospital admissions.
- The authorised copy of the challenged will, in order to examine how the assessment of capacity was recorded.
- The disability or dependency assessment, if one was applied for, with its date and its findings.
- The bank statements for the surrounding months, which reveal unusual disposals and changes of account holders.
- Evidence from carers, neighbours and health staff about the testator's actual state during those days.
What closes the door
- Producing only the diagnosis of the illness. Article 666 requires regard to be had only to the state at the moment the will was made, not to the general course of the disease.
- Giving the case up because the notary recorded that she had capacity. That assessment is given in a short interview and yields to medical evidence to the contrary.
- Signing the division or taking the legítima without expressly reserving the claim, thereby carrying out the very will you later ask to have annulled.
- Requesting the medical record only once the claim has been filed. Without that material the expert cannot place the stage of the illness on the exact date.
- Challenging without checking which will would revive: sometimes the earlier one divides the estate less favourably than the one being attacked.
The law that applies
- Art. 663 CC. A person under fourteen may not make a will, nor may a person who, at the moment of making it, cannot form or express their wishes even with the help of aids or support. This is the threshold the claim must prove. BOE-A-1889-4763
- Art. 666 CC. In assessing the testator's capacity, regard shall be had only to the state she was in at the time the will was made, which concentrates all the evidence on one specific date. BOE-A-1889-4763
- Art. 665 CC. A person with a disability may make a will when, in the Notary's judgment, they understand and can express the scope of their provisions, and the Notary must support their understanding and reasoning with whatever adjustments are needed. BOE-A-1889-4763
- Art. 685 CC. The Notary must know the testator or identify her with two witnesses or with official documents, and must satisfy himself that, in his judgment, she has the legal capacity needed to make a will. BOE-A-1889-4763
- Art. 664 CC. A will made before mental incapacity set in is valid, so a later deterioration does not drag down what was made while the person still had her lucidity. BOE-A-1889-4763
- Art. 1301 CC. The action for annulment lapses after four years, and the article lists the starting day in cases of intimidation or violence, mistake, fraud or false cause, contracts by minors, persons with disabilities acting without support, and acts by one spouse without the other's consent. BOE-A-1889-4763
Each article checked against the consolidated text published in the BOE (the Spanish official gazette).
Frequently asked questions
The notary wrote that she had capacity. Can I still win?
Yes, though starting from an unfavourable position. Article 685 requires the Notary to satisfy himself that, in his judgment, the testator has the legal capacity needed, and that record is made after a short interview and without medical notes to hand. It yields to evidence to the contrary, and that evidence is documentary and medical: dated reports, cognitive tests and witnesses who were with her during those days.
My mother had a diagnosis of Alzheimer's. Is that not enough?
It is not enough. Article 663.2 requires that at the moment of making the will she could not form or express her wishes even with the help of aids or support, and article 665 expressly allows a person with a disability to make a will when they understand the scope of their provisions. A diagnosis sets the starting point, but what decides the case is the stage of the illness on the exact date the will was made.
If I win, which will applies?
The earlier one, if there is one and it was valid, which is why it should be examined before suing. It may turn out that the previous will divides the estate less favourably for you than the one being challenged, and then the case loses its economic point. If there is no earlier will, the succession opens without one and the heirs are determined by law, a scenario that must also be worked out before taking the step.
Can I request my mother's medical records now that she has died?
Access by relatives to the medical record of a deceased person is provided for in health legislation and is one of the first steps in the case, because without that material the expert cannot place the stage of the illness. Where the centre refuses or hands over incomplete documentation, the route is to ask for it to be brought into the proceedings so that the health service is required to produce it directly.
My sister took my mother to the notary and chose the notary. Does that count?
It counts as an indication, not as proof on its own. That the beneficiary arranged the appointment, went with her and changed the usual notary's office are facts the court weighs alongside the rest, especially where the new will abruptly alters a division that had held for years. That set of circumstances is what gives context to the medical report and strengthens the account.
This guide explains how the action works in general. It does not replace the study of your own case: deadlines depend on when things happened and on what you have done since.