Two registrations, at two authorities that do not talk to each other. Several of the decisions you take that day cannot be undone for months.

Two counters, not one

Becoming autónomo is not one formality, it is two. One at the tax office, which enters you in the census of businesses, professionals and withholders. One at the social security treasury, which registers you in the RETA, the special scheme for self-employed workers.

	Tax office	Social security
What you file	Form 036	RETA registration
When	Before you start trading	From the start date, and it can be brought forward by up to sixty calendar days
What it decides	Activity code, recurring obligations, VAT, withholding	Your contribution base, your mutua, your cover
What it costs	Nothing	The monthly contribution, from the day you start

The IAE activity code is the decision that lasts longest

Form 036 asks which activity code you will trade under. It looks like paperwork and it is the opposite: the code defines what you are entitled to invoice for, and almost everything else hangs off it. The first fork is between the two sections of the tariff.

	Section one · business	Section two · professional
Who	Retail, hospitality, manufacturing, transport, letting	Activities carried on with a qualification: lawyers, architects, designers, developers, consultants
Withholding on your invoices	None	15 %, or 7 % in your first year and the two that follow
Quarterly form 130	Yes	No, if at least 70 % of your income was invoiced with withholding

The classic mistake is choosing a code that is too narrow. Register only for "software development" and then start delivering training, and that second invoice is not covered: the census has to be extended first, not afterwards. The opposite mistake — ticking six codes just in case — also has a cost, because each one brings its own obligations.

Very few self-employed people actually pay the IAE tax itself: it is only due once you pass two years of activity and a million euros of turnover. Declaring the code and paying the tax are different things.

The boxes that set the next few years

• VAT. Standard scheme, equivalence surcharge or exempt activity. Quarterly form 303 and the annual 390 come from here.
• Income tax. Direct assessment, simplified or normal, and whether form 130 applies to you.
• Withholding. If you will have staff (form 111) or rent business premises (form 115).
• Intra-EU transactions. Box 582 is the one that applies for the ROI, the register you must be on to trade with businesses in other EU countries. We apply for it on form 036.
• Working from home. If you want to deduct utilities, the proportion of the home used for the business is declared here. Deducting 30 % of the utilities on that proportion without having declared it first hands the argument away in any review.

Your contribution is no longer entirely your choice

Since 2023 the self-employed contribute on real net earnings. You pick a base inside the bracket that matches what you expect to earn, you pay on it through the year, and the following year social security compares your actual earnings with what you paid and settles the difference either way.

That changes the old advice. Choosing an artificially low base no longer saves anything, it only defers; choosing a high one without needing to ties up money for fifteen months.

The flat rate

We handle the RETA registration for you, with your social security number and your IBAN, and with the contribution base and the mutua chosen with you before anything is filed. You do not have to log into any government portal or book an appointment.

The flat rate: 86 € a month for the first year

The reduced contribution under article 38 ter of Law 20/2007 is one of the few reliefs still worth having. Instead of the contribution your earnings bracket would call for, you pay 86 € a month for the first twelve months. The ordinary minimum for someone starting out is around 200 €, and higher for anyone declaring average earnings, so the saving over a first year is commonly between 1,500 € and 3,000 €.

Condition	What it actually means
Not recently self-employed	No RETA registration in the two years immediately before. Three if you already had this same relief once.
Claim it	It is not automatic. It is applied for when you register, and a month that passes without it is not recovered.
Be up to date	No outstanding debts with social security or the tax office. If there are, they have to be cleared within the period you are given.
Stay registered	Deregister and come back, and the two-year clock starts again from zero.
Repay it if it lapses	If a condition is breached, the amount reduced is reclaimed. It is a conditional relief, not a gift.

While the reduced contribution lasts there is no upward settlement for that period: you pay those 86 € regardless of what you end up earning. Which is why it is worth not losing it simply by not asking.

The amount is set by each year's legislation, so we confirm it with you at the moment of registration. And if you do not qualify, we tell you what your real contribution will be before registering anything, not after.

What happens if you register late

Invoicing without being registered is not a grey area: it is two separate breaches, one at each authority. Social security registers you retroactively and claims the unpaid contributions with a surcharge — and a retroactive registration carries no right to the flat rate. The tax office regularises the unreported VAT and income tax, with a surcharge if you come forward first or a penalty if their letter arrives first. The gap between those two outcomes is usually thousands of euros, and it depends only on who moves first.

Your case, in two minutes

What applies to your self-employed registration, in two minutes

The form for this service asks only what matters here. At the end you have your map of obligations, the deadlines running against you and a fixed price.

Start with this form →

What comes after registering

Registering takes a day. What comes after it happens every quarter: the Modelo 303 for VAT, the Modelo 130 for income tax if it applies to you, the Modelo 349 when you invoice clients elsewhere in the European Union, the statutory books kept up to date, and the annual summaries in January.

Two dates are worth writing down on the day itself. The first quarterly return covers the period in which you registered, even if you registered on its last day, and it falls due in the twenty days after that quarter closes. And the contribution base you chose is a forecast, not a commitment: if what you actually earn moves away from it you can change it during the year, and social security settles the difference afterwards against your real income.

You do not have to decide today who carries that. What matters on the day you register is knowing which returns you will owe: almost every penalty in a first year comes from not knowing a deadline existed, not from disagreeing with it. If you would rather it was handled, the recurring service is self-employed, from 69 € a month with taxes included, and invoicing abroad when your clients are outside Spain.

If you are claiming unemployment benefit

Then the order changes completely and registering is no longer the first step. There are three ways of combining a Spanish unemployment benefit with self-employment, they exclude one another, and all of them are applied for beforehand or within very short deadlines. That case goes through benefit plus self-employment, which includes the full registration in the price.

How we do it

You fill in the form — eight questions — and from that we already know which activity codes apply, which boxes to tick and whether you qualify for the reduced contribution. Then we talk for fifteen minutes to settle the two things nobody can decide for you: the contribution base and your cover.

We file form 036 and the RETA registration, send you both receipts, and give you a calendar of every return due over the following twelve months, with its dates. 210 €, taxes included, once. We work in English, Spanish and French.