What this letter is
It tells you that Hacienda (the Spanish tax authority) has reviewed one of your tax returns, almost always the income tax return (la renta), and disagrees with some figure. It explains what has changed and how much you would have to pay, or how much less you will be refunded. It isn’t a debt yet: it is a propuesta (proposal), and you have a period to give your side.
It usually comes as part of a verificación de datos (data check) or a comprobación limitada (limited audit). Sometimes you were sent a requerimiento (information request) beforehand; other times the proposal is the first letter.
How to read it: the key parts
| What you see on the letter | What it means |
|---|---|
| Comunicación de inicio / procedimiento de comprobación limitada or verificación de datos (notice of start / limited audit / data check) | The type of review. A limited audit can last up to 6 months. |
| Referencia and CSV (código seguro de verificación) (reference and secure verification code) | Details that identify the letter and link your objections to it. |
| Concepto / Ejercicio (tax / tax year) | The tax and year reviewed, for example IRPF (income tax) 2024. |
| Motivación / Hechos y fundamentos (reasons / facts and legal grounds) | The explanation of why they are changing your return. This is the most important part. |
| Liquidación propuesta (proposed assessment) | The new calculation: tax due, what you already paid or were refunded, and the difference. |
| Intereses de demora (late-payment interest) | Interest for the time since you should have paid. In 2026, 4.0625 % a year. |
| Plazo de alegaciones (period for objections) | The days you have to reply, between 10 and 15 working days. |
What deadline you have
To submit alegaciones (objections) you have between 10 and 15 working days. Your letter says exactly how many. They count from the day after notification, excluding Saturdays, Sundays and public holidays.
Example: you open the proposal on the portal on a Thursday and you are given 10 working days. You start counting on Friday. If there are no holidays, the period ends on the Thursday two weeks later.
If it is an electronic letter and you don’t open it within 10 calendar days, it is treated as notified and the period starts running anyway.
What you can do
| Option | When it makes sense | What happens next |
|---|---|---|
| Submit objections with evidence | If you have documents that contradict the change (invoices, contracts, certificates) | Hacienda considers them and may correct or keep the proposal. |
| Agree (dar conformidad) | If you see Hacienda is right | You can say so in writing on the portal. Then the assessment arrives with its payment period. |
| Do nothing | If you agree and don’t mind waiting | The provisional assessment is issued exactly as proposed. |
| Appeal later | If the assessment arrives and you still disagree | Recurso de reposición (appeal for reconsideration) or reclamación económico-administrativa (claim before the tax tribunal), 1 month each. |
| Ask to defer payment | When the assessment arrives and you can’t pay it all | Requested on the portal within the payment period. |
What happens if you do nothing
- Hacienda issues the liquidación provisional (provisional assessment) with the proposal’s figures.
- You receive a payment letter. If you are notified between the 1st and the 15th, you pay by the 20th of the following month. If it’s between the 16th and the end of the month, by the 5th of the second month after.
- If you don’t pay that either, the providencia de apremio (enforcement notice) arrives with a surcharge.
- If the difference is due to unpaid tax, a separate expediente sancionador (penalty procedure) may be opened.
Common mistakes
- Paying the proposal. It isn’t paid yet; wait for the assessment.
- Objecting without evidence. Saying “I disagree” isn’t enough. Attach documents.
- Arguing about things that didn’t change. Focus on the figure Hacienda has modified.
- Thinking it’s a fine. Any penalty comes in a separate letter.
- Missing the deadline and trying to object afterwards. You can still appeal, but the road is longer.
How to respond, step by step
- Open your original return and the proposal, and find the figure that changes.
- Read the motivación (reasons) carefully: that’s where the why is.
- Gather your evidence in PDF: invoices, certificates, contracts or bank receipts.
- Log in to the AEAT portal with Cl@ve, a certificado digital (digital certificate) or DNIe (electronic ID card).
- Use the procedure “Contestar requerimientos o presentar documentación relativa a notificaciones” (answer requests or submit documents related to notifications) and enter the reference or CSV.
- Write your objections or your agreement, attach the documents and download the justificante (receipt).
- Without digital access, submit them at an AEAT office or at any public registry.
Sample text (write it in Spanish):
En relación con la propuesta de liquidación provisional con referencia [número o CSV], relativa a [IRPF ejercicio], notificada el [fecha], presento las siguientes alegaciones: [explica el dato y por qué es correcto]. Aporto como prueba: 1) [documento]; 2) [documento]. Solicito que se tengan en cuenta y se modifique la propuesta. [Nombre, NIF, fecha]
(In English: regarding the proposed provisional assessment with reference [number or CSV], concerning [income tax, year], notified on [date], I submit the following objections: [explain the figure and why it is correct]. As evidence I attach: 1) [document]; 2) [document]. I request that they be taken into account and the proposal be amended. [Name, NIF, date])
Cartamiga tip: if on review you see that Hacienda is right (for example, you forgot some income), don’t waste energy objecting. Get ready to pay the assessment on time. If the difference seems unfair and you have the papers, objecting now is simpler than appealing later.