Lorena Pastor, a pharmacist in Castellón de la Plana, sold the flat in El Grao, the town's seaside district, where she had lived since 2014, in November 2025. She had 50,000 € of mortgage left, which was paid off at the signing before the notary; the transfer value, after costs, was 230,000 €, and the gain 60,000 €. She has moved into rented accommodation while a development in Benicàssim, where she has reserved a home, is finished; the deed will not be signed until autumn 2026. In April 2026 she receives the draft of her 2025 income tax return and sees that nothing about the sale appears. She wants to know what she has to put, where, and what happens if she puts nothing.
What the Regulations require
Article 41.3 of the Regulations on IRPF (Spanish personal income tax) provides that, when the reinvestment is not made in the same year as the sale, the taxpayer "shall be obliged to record in the tax return for the year in which the capital gain is obtained their intention to reinvest under the conditions and within the periods indicated".
Three ideas follow from this. The obligation arises only if the reinvestment is not made in the year of the sale. It is met in the return for the year of the sale, not in the return for the year of the purchase. And what is recorded is an intention, which will then have to be fulfilled within the two years.
When it has to be recorded and when not
| Situation | What is shown in the return for the year of the sale |
|---|---|
| Sale and purchase in the same year | The gain exempt because of reinvestment already made |
| Purchase in the two previous years and payment with the sale in the same year | Reinvestment already made |
| Sale in one year and purchase in the next or the one after | The exempt gain with the intention to reinvest |
| Part already reinvested and part pending | What has been reinvested and the intention for the rest |
| Only part is intended to be reinvested | The intention for that part; the remaining proportion is taxed |
| No reinvestment is going to be made | The whole gain, with no exemption |
Lorena is in the third row: she sold in 2025 and will buy in 2026. She has to declare the sale in her 2025 return as a transfer of her main home, give the total amount obtained and record that she will reinvest it. The software of the Agencia Tributaria (the Spanish tax agency) has a specific section for reinvestment in the main home within the declaration of gains on the transfer of property; the draft return, on the other hand, does not usually include any of this and it has to be completed by hand.
The figures that are entered
- Transfer value: 230,000 €.
- Acquisition value, with the costs of the 2014 purchase: 170,000 €.
- Capital gain: 60,000 €.
- Principal of the mortgage paid off on the sale: 50,000 €.
- Total amount obtained: 230,000 − 50,000 = 180,000 €.
- Amount she expects to reinvest: 180,000 €.
- Gain declared exempt: 60,000 €.
- Gain taxed in 2025: 0 €.
If Lorena only expected to reinvest 135,000 €, the exempt part would be 60,000 × 135,000 ÷ 180,000 = 45,000 €, and 15,000 € would be taxed in 2025. The proportion is explained in if I reinvest only part, how much is exempt?. The guide on declaring the reinvestment exemption walks through the income tax software.
If it is forgotten before the campaign ends
Imagine that Lorena files her return in May by accepting the draft as it is, without the sale. While the filing period is still open, the fix is simple: she files a new return that includes the sale and the intention to reinvest. Article 119.3 of the General Taxation Law, which limits changes to options exercised in a return, expressly allows them to be changed if the change is filed within the regulatory filing period.
The same applies if she declared the sale but let it be taxed in full because she did not know she could reinvest: within the campaign, it is corrected without much difficulty.
If it is forgotten and the campaign has already ended
This is where the problems begin. Hacienda, as the Spanish tax office is commonly called, may argue that the reinvestment exemption works as an option that had to be exercised in the return and that, under article 119.3, it can no longer be added after the campaign. Against that position, it can be argued that the exemption depends on substantive requirements, such as actual reinvestment and main home status, and that a formal defect should not deprive someone who meets them of it. It is an open debate, and its outcome cannot be guaranteed.
The most common situations outside the campaign are these:
- She declared the sale without the exemption and paid: she can ask for the return to be corrected and for a refund, knowing that the tax authorities may invoke article 119.3.
- She did not declare the sale at all: if Hacienda detects it, it will assess the gain, and the exemption will have to be defended within that procedure, with the evidence of the reinvestment.
- She declared the sale as exempt because of reinvestment already made when it was in fact still to come: the mistake is one of classification and can usually be explained, provided the reinvestment is made in time.
Buying the new home within the two years does not replace recording the intention in the return for the year of the sale. If the omission is discovered outside the campaign, we do not guarantee that the exemption can be recovered. What is in your hands is not getting into that situation: whenever you have sold a home, review the draft before confirming it.
If you have a return already filed with this problem, the reinvestment form allows us to see exactly what situation you are in before deciding which document it is best to file. How correction works in general is explained in how to correct a return already filed.
What happens in the following years
Recording the intention does not close the matter. Lorena has until November 2027 to reinvest the 180,000 € in the home in Benicàssim and, after that, twelve months from the deed to move in. If the development is delayed or she finally decides not to buy, the declared intention is not fulfilled and she will have to correct the gain in her 2025 return by means of a supplementary return, as we explain in I am not going to reinvest after all: what do I do?.
The exact dates of her window are in the two years: from when and until when. And if she bought off-plan with delivery after November 2027, the risk she would run is the one we describe there for developments that drag on.
What is worth keeping from day one
Together with the 2025 return, Lorena should file away the deed of sale, the bank's certificate showing the principal paid off, the 2014 purchase deed with its costs, the reservation contract for Benicàssim and a table with the calculation of the amount obtained. When she buys, she will add the new deed and the proof of payment. They are not submitted with the return, but they are the first thing requested if a check arrives.
The step from intention to actual reinvestment, with its calculations and time limits, is supported in the Salama Tax service for selling your main home.