Elena runs a dental clinic in Zaragoza as a self-employed person. Since January 2024 she has worked with a collaborating dentist who invoices her for the procedures he carries out in her practice: 22,000 € in 2024 and 26,000 € in 2025. The gestoría (the accountancy firm) that handled her taxes applied 7 % withholding to those invoices, the rate for professionals who are starting out. The collaborator had been practising for more than ten years and never stated in writing that he was just starting. In June 2026 a request (requerimiento) arrived about the 2024 Modelo 111. The difference between what was withheld and what should have been withheld added up to 3,840 €.
Elena asked what anyone in her place asks: if the gestoría made the mistake, why are they writing to me? And, above all, who ends up paying each euro?
As far as Hacienda is concerned, she is the one who withholds
The law places the obligation to withhold and pay over on whoever pays, not on whoever handles their paperwork. Hiring a professional does not transfer that obligation: Elena is still the taxpayer responsible, and the Administration claims from her the withholding she should have made, with its late-payment interest and, where applicable, the penalty. That is not a debatable opinion; it is the starting point for any analysis.
What can be argued, along separate routes, are three things: whether there was fault for the purposes of the penalty, who kept the money that was not withheld, and what part of the cost is damage caused by the adviser.
The figure, broken down
| Year | Collaborator's invoices | Withheld at 7 % | Due at 15 % | Difference |
|---|---|---|---|---|
| 2024 | 22,000 € | 1,540 € | 3,300 € | 1,760 € |
| 2025 | 26,000 € | 1,820 € | 3,900 € | 2,080 € |
| Total | 48,000 € | 3,360 € | 7,200 € | 3,840 € |
Because the request had already arrived for 2024, that part can no longer be put right with a recargo (the surcharge for filing late unprompted): it is assessed within the procedure. Each quarter is a separate offence and, in this case, the base of each one is small and there was no withholding deducted and not paid over, so a minor classification is to be expected, with a fine of 50 %. On the 1,760 € for 2024 that would be 880 €; with the 30 % reduction for agreeing to the assessment it comes down to 616 €, and with the 40 % reduction for prompt payment, to 369.60 €. Late-payment interest is added to that.
For 2025, if there is no request yet, the sensible thing is to file the supplementary returns (complementarias) for its four quarters now. That way the 2,080 € carry the article 27 recargo and not a penalty. How to order that when several periods are involved is in the order for correcting several tax years.
Where the missing money really is
Here is what almost nobody explains. The income tax (IRPF) Act provides that, when withholding was not made, or was made for less than it should have been, for reasons attributable to the payer, the recipient deducts in his own return the amount that should have been withheld from him. Elena's collaborator can therefore deduct 15 % even though only 7 % was taken. For two years he received 3,840 € more in net terms than he was entitled to, and now that same amount is being claimed from the clinic.
The practical consequence is that the tax itself is not, in principle, damage to be claimed from the gestoría: the collaborator has that money. What you do is claim it from him, with the invoices and the contract in hand, as a civil matter. If the collaborator had asked in writing for 7 %, stating he was starting out, the analysis would be different, because the cause of the mistake would no longer lie with the payer. That is why the first thing we ask for in a case like this is that statement, if it exists.
The penalty: fault can be argued, the debt cannot
The penalty regime requires fault. It is not enough for the result to be wrong; there must be at least negligence. Having entrusted the calculation to a professional does not on its own exclude the taxpayer's liability, according to settled administrative and court practice, but it is a factor that is weighed, together with how diligently the documents were handed over and how complex the question was. In this case the 7 % rule is not obscure, so the defence of no fault has limited scope, and it is best to say so before raising it. It is developed in the penalty and its reductions, which also explains when it makes sense to agree in order to keep the reduction.
If your case resembles this one and a letter is already involved, tell us in the self-employed form: the first thing is to answer properly within the deadline, and the second is to separate what is debt, what is penalty and what is damage.
What can be claimed from the gestoría, and how it is proved
The damage that can be attributed to the adviser, if there was negligence, is what would not have been paid had the work been done properly: the penalty, the late-payment interest, the cost of putting things right and, where applicable, whatever cannot be recovered from the collaborator. The route is civil: the services contract and, behind it, the professional indemnity insurance most firms have in place. There is no guarantee that it will pay; what there is is an orderly way of asking.
- The engagement letter (hoja de encargo) or, failing that, the emails showing that the gestoría handled the 111 and calculated the withholding.
- What was handed over and when: the collaborator's invoices, the collaboration agreement and any information about how long he had been practising.
- Whether or not it asked for the 7 % statement. A diligent adviser asks for it before applying the reduced rate; that it did not is the core of the claim.
- The exact cost: the assessment, the penalty, the interest and the invoices of whoever corrects the mistake.
It is tempting to leave the request in the hands of the same gestoría that got it wrong and concentrate on holding it to account. They are two separate fronts, and the first has a deadline: if the request is not answered properly, the assessment and the penalty arrive anyway, and whatever is claimed afterwards does not cancel them.
What gets done this very week
With the request on the table, the order of work in Elena's case was this. First, answer within the deadline, providing the collaborator's invoices and acknowledging the rate error, because disputing the obvious only uses up the reduction for agreeing. Second, file the 2025 supplementary returns before the request is extended to that year. Third, ask the collaborator to put 15 % on his invoices from then on, and open the conversation with him about the 3,840 € he received in excess.
And fourth, write to the gestoría. Not to argue, but to put things on record: what was found, when, what it costs, and that it is asked to notify its insurer. That letter, sent early and with the figures, is the basis for any later claim.
The other possible mistakes in a 111
Not all of them are about the rate. We also see payroll withholding calculated without updating the worker's family details, professionals' invoices put in the quarter in which they were received rather than the one in which they were paid, and a January 190 that does not match the sum of the four quarters. Each is corrected in a different way, but they all share one rule: you correct the quarter that is wrong, not the summary so that it adds up. You have the map of the most common withholding in the guide to Modelos 111 and 115.