When you file a return late and nobody has asked you for it, there is no fine: there is a recargo, a surcharge for filing late without being asked. It is governed by article 27 of the Ley General Tributaria, Spain's General Tax Act. It rises month by month, it carries a reduction that many people leave unused, and there is one situation in which it is not charged at all. This guide works it out step by step, because the difference between filing this week and filing next month is measured in percentage points.
When it applies
The late-filing surcharge requires two things at the same time: that the self-assessment (autoliquidación, the return in which you calculate and pay the tax yourself) or return is filed after the end of the statutory deadline, and that it is filed without a prior request from the tax authorities. If the second is missing, there is no surcharge: there is an assessment and, most likely, penalty proceedings. Exactly what counts as a prior request is set out in its own guide, and it is worth reading first, because it is the boundary for everything else.
The surcharge is calculated on the amount payable resulting from the late self-assessment. If the return comes out at zero or with a refund, there is no base to apply it to and the surcharge does not exist. That does not rule out a penalty for filing late a return that causes no financial loss, which is a different matter.
The scale, month by month
The surcharge is 1 %, plus a further 1 % for each full month of delay after the end of the period for filing and paying. Months are counted from date to date; anything short of a full month does not add.
| Delay | Surcharge | Late-payment interest |
|---|---|---|
| Less than 1 month | 1 % | No |
| 1 full month | 2 % | No |
| 2 months | 3 % | No |
| 3 months | 4 % | No |
| 4 months | 5 % | No |
| 5 months | 6 % | No |
| 6 months | 7 % | No |
| 7 months | 8 % | No |
| 8 months | 9 % | No |
| 9 months | 10 % | No |
| 10 months | 11 % | No |
| 11 months | 12 % | No |
| 12 months or more | 15 % | Yes, from the day after the 12 months end |
Up to twelve months no late-payment interest accrues: the surcharge takes its place. From that point the surcharge freezes at 15 %, but interest starts running, calculated from the day after the twelve months are completed until the day the self-assessment is filed. The late-payment interest rate is set each year by the Ley de Presupuestos, the annual state budget act, so over a long delay you apply the rate for each period, not a single one.
Two complete calculations
| Case A: four months and ten days late | Amount |
|---|---|
| Tax payable under the self-assessment | 8,400.00 |
| Full months of delay | 4 |
| Surcharge: 1 % + 4 % | 5 % → 420.00 |
| 25 % reduction if the conditions are met | −105.00 |
| Total to pay | 8,715.00 |
| Case B: twenty months late | Amount |
|---|---|
| Tax payable under the self-assessment | 12,000.00 |
| Flat surcharge for exceeding twelve months | 15 % → 1,800.00 |
| 25 % reduction if the conditions are met | −450.00 |
| Late-payment interest for the eight months beyond twelve | At the rate in force for each period |
| Total | 12,000 + 1,350 + interest |
Note that in case B the tax is paid at the moment of filing, while the surcharge comes later, in a separate assessment notified by the tax authorities. Interest is not reduced: the 25 % reduction works only on the surcharge.
The 25 % reduction, and the two conditions that hold it up
The surcharge is reduced by 25 % provided that both of these are met:
- The remaining amount of the surcharge, the 75 %, is paid within the voluntary payment period that opens when the surcharge assessment is notified. That period is the one in article 62.2: if the notification is received between the 1st and the 15th of the month, until the 20th of the following month; if it is received between the 16th and the last day of the month, until the 5th of the second month after.
- The whole debt resulting from the late self-assessment has been paid at the time of filing, or within the article 62.2 period opened by notification of the corresponding assessment.
If, instead of paying, you ask to defer or pay in instalments, the 25 % reduction is kept only when the application is made with a guarantee in the form of a joint and several guarantee from a credit institution or mutual guarantee company, or a surety insurance certificate. A deferral without a guarantee, of the kind granted for smaller amounts, does not keep the reduction. It is the detail we have most often seen overlooked, because the application is convenient and the cost shows up later. How deferral works is in deferring or paying in instalments, and the specific case in deferring what comes out of regularising back years.
If, after the reduction has been applied, either condition is breached (for example, the 75 % is not paid on time), the tax authorities claim the amount of the reduction with no further step than a notification.
The case in which no surcharge is charged
Since the 2021 reform there is one case in which late filing generates no surcharge at all. It arises when the taxpayer regularises, by self-assessment, other periods of the same tax following the facts or circumstances that the tax authorities already corrected in an earlier assessment. Four conditions are needed:
- The self-assessment must be filed within six months of notification of the tax authorities' assessment.
- There must be full acknowledgment and full payment of the resulting amounts.
- No request for rectification, appeal or claim may be lodged against that earlier assessment.
- No penalty may arise from the authorities' correction.
It is a narrow door but a very useful one: when a review of one year exposes the same mistake in the neighbouring years, regularising them quickly and on the same terms costs nothing in surcharges. It means giving up the right to dispute the original assessment, so the decision is taken by comparing the amount at stake with the cost of an appeal.
Which amount it is calculated on
The base of the surcharge is the amount payable resulting from the late self-assessment, not the omitted income or the value of the asset. In a supplementary return (complementaria), that amount is the difference between what comes out now and what was paid at the time, because the supplementary return only adds what was missing. And if one year needs several things corrected, it is better to do it in a single self-assessment: two supplementary returns for the same period produce two surcharge assessments and multiply the paperwork without saving anything.
There is a nuance for late returns that are not self-assessments, that is, those where the tax authorities calculate the tax on the basis of what is declared. The typical example is inheritance tax (the Impuesto sobre Sucesiones) in regions that work on that system. There, the surcharge is calculated on the amount of the assessment issued, and the payment period for keeping the 25 % reduction is the one opened by that notification.
What the surcharge is not
The surcharge is not a penalty. It requires no fault, it is not dealt with in separate proceedings, it leaves no penalty record and it does not qualify for the reductions for agreement or prompt payment that apply to penalties. Nor is it interest: it is an accessory charge that the law fixes as a percentage. The three are compared in surcharge, interest and penalty, and telling them apart is what lets you decide whether an appeal is worthwhile.
Nor should it be confused with the enforcement-period surcharges, which are something else: those arise when a debt already assessed is not paid within the voluntary period, and they range from 5 % to 20 % depending on timing, with interest in the highest band. You can have an article 27 surcharge for filing late and then an enforcement surcharge for not paying it.
The sum to do today
The surcharge goes up on the day each full month is completed, not at the end of the calendar month. If the deadline ended on 30 June and today is 27 October, you have three full months behind you and stand at 4 %; on the 30th you move to 5 %. Filing three days earlier saves one percentage point of the tax, which in a regularisation of any size is not small change.
And there is a much bigger cost than the calendar: a formal request arriving before you file. At that moment the surcharge disappears and what is left is the assessment plus a penalty, which starts at 50 % of the unpaid tax. That is why the decision is rarely "when" but "now". If you have back years and do not know where to start, the order is in in what order to regularise several years, and you can tell us about the case through the late filing form. We calculate the exact surcharge and the total cost before filing anything, and we warn you of the risks we see: what we do not do is guarantee that the tax authorities will not open proceedings while you are getting the papers ready.