The quarter, which is what really takes the time
A self-employed person on the ordinary method of assessment files, each quarter, Modelo 303 for VAT and Modelo 130, the instalment payment on account of income tax. About the second there is one thing almost nobody has clear: the 130 is not a tax, it is an advance on next year's income tax return. What you pay in there is deducted later, which is why in June some people meet a refund they were not expecting.
The words behind the forms are worth having. A self-employed person in Spain is an autónomo, registered both with the Agencia Tributaria through Modelo 036 and with the social security system, which charges a monthly contribution independent of the tax. Estimación directa, the ordinary method of assessment, taxes real income less real costs, and it is what almost every professional falls under. None of that changes with the city, but it is the frame every quarterly form sits in.
There is also an exemption from the 130 where most of your income already arrives with withholding applied by your clients. Deciding that properly at the start saves a whole year of pointless filings. We explain it in Modelo 130 and in Modelo 303.
Withholding: Modelos 111 and 115
The moment you have someone on the payroll, pay a professional or rent commercial premises or a warehouse, you appear as a withholding agent. Modelo 111 gathers the withholding on employment income and on professionals' fees; Modelo 115, the withholding on the rent of urban property.
The failure we have had to repair most often in this city is always the same: years of paying the rent on the premises without withholding, because the landlord said it was not necessary. The obligation belongs to the tenant, not the landlord, and so does the liability. It is in Modelos 111 and 115.
Filing late but on your own initiative carries the surcharge in article 27 of the Ley General Tributaria, the general tax act, which is a known quantity. Waiting for the enquiry letter to arrive changes the frame: from that point a penalty becomes possible. The difference between the two is in surcharge against penalty.
Sole trader or company?
This is the recurring conversation once profits rise. There is no magic number, and be wary of anyone who gives you one from memory: the crossover depends on your real marginal rate, on how much money you need to take out of the company each year, and on the cost of keeping it alive, which is fixed and is paid whether the year goes well or badly.
We do it with your figures, not with a textbook example, and we show you both scenarios on the same sheet. The general comparison is in sole trader or limited company.
One warning about that comparison. A company is not only a tax rate: it means accounts filed at the Registro Mercantil, the commercial register, a separate corporation tax return, and a decision every year about salary or dividends. Those costs are certain, while the saving depends on assumptions. Both sides of that go on the sheet.
Who writes to us from Zaragoza
| Who | What they usually face |
|---|---|
| Self-employed professional with corporate clients | Withholding on their invoices, exemption from the 130 and the annual reconciliation |
| Workshop or small shop with a rented unit | Modelo 115 every quarter and the annual summary on Modelo 180 |
| Self-employed person with a new foreign client | Registration on the ROI, Modelo 349 and where the service is deemed supplied |
| Someone who has just registered | Modelo 036 — the 037 no longer exists — the IAE heading and a full first quarter |
| Neighbour letting an inherited flat by the month | Property income, deductible costs and depreciation |
How we work with clients in Zaragoza
Fixed price and closed quarter. You leave the invoices issued and received in your folder as they arise, the bank statements and not much else; we send back the summary with the amount payable before anything is filed, so that there is no surprise on the 20th.
If you arrive dragging something — a 115 that was never filed, an annual VAT summary that does not reconcile, a blank quarter — we put it in order first and tell you frankly what fixing it costs and what not fixing it risks. We are never going to guarantee you an outcome against the tax authority; we are going to tell you what we are counting on and what we are not.
One more habit: we tell you what the year will look like before it starts. A single sheet with the forms that are yours, the months they fall in and who prepares each one avoids most of the late filings we are later asked to repair. It is not clever work, and it is the part clients say afterwards that they valued most.
A Modelo 303 filed late in Zaragoza: what it costs, month by month
An installer from the north bank of the Ebro closes the fourth quarter of 2025 with 2,400 € of VAT to pay. The deadline ended on 30 January 2026 and he missed it. If he files on his own initiative, before the tax authority writes to him, he pays the surcharge in article 27 of the General Tax Act: 1 % plus one point for each full month of delay, and from twelve months onwards 15 % plus late-payment interest.
| Filed on | Full months late | Surcharge | Amount |
|---|---|---|---|
| 20 February 2026 | 0 | 1 % | 24 € |
| 15 June 2026 | 4 | 5 % | 120 € |
| 10 December 2026 | 10 | 11 % | 264 € |
| 15 March 2027 | More than 12 | 15 % + interest | 360 € plus interest from the point the twelve months are reached |
The lesson of the table is not that the surcharge is cheap: it is that it grows every month and that it has a known ceiling. What has no known ceiling is waiting for an enquiry letter, because at that point the talk is no longer of surcharges. The calculation with your own dates is in calculating the article 27 surcharge, and if you have quarters outstanding, the form is the one for voluntary regularisation.
The year of a Zaragoza workshop with one employee and rented premises
| Deadline | Modelos |
|---|---|
| 1 to 20 April, July and October | 303 for VAT, 130 for income tax, 111 for the payroll and 115 for the rented unit |
| 1 to 30 January | The same four for the fourth quarter and the Modelo 390 for VAT |
| 1 to 31 January | 190 and 180, the annual summaries of the 111 and the 115 |
| February | 347, if more than 3,005.06 € was reached with any customer or supplier in the year |
| From April to 30 June | Income tax return for the previous year, subtracting what was paid in advance through the Modelos 130 |
That is some twenty filings a year for a two-person business. None is difficult; the difficulty is making sure none slips through in a busy month. That is why we work to the direct-debit deadline, which falls earlier, and not to the 20th.
The month that gets most complicated is January: the four returns for the fourth quarter, the three annual summaries and the year-end accounts all coincide, just when the workshop has to invoice the jobs finished in December. What we do is bring forward to December everything that can already be reconciled — payroll, rents, withholdings — so that in January only the VAT for the last quarter is left.
Since contributions have been based on actual income, the amount you pay each month is provisional: you choose it by bands according to what you expect to earn, and when Social Security receives your final profit figure from the tax authority, it compares and adjusts. A good year with a low contribution is paid for later in one go, when the money has already gone on something else. You can change band during the year, and it is worth doing as soon as your Modelos 130 show you are running above forecast. It is in contributions based on actual income.