Self-employed in Spain: What's a contribution base and which should I choose?

Are you an autónomo in Spain who can't get their head around the social security system? Want to find out if you can pay less in fees and which contribution base you should choose? Here's what to know about the system and how to 'cotizar' in Spain.

What does it mean to ‘cotizar’ in Spain?

If you’re self-employed (autónomo) in Spain you’ve probably come across the word cotizar, which in this context means to contribute or pay contributions to something.

Basically it means contributing to the Spanish welfare state by paying taxes. You contribute a portion of your salary to the social security system in order to receive benefits, such as access to the healthcare system or perhaps a pension when the time comes, and the more you contribute, the more you receive.

This so-called contribution ‘base’ will partly determine the retirement package you receive. In basic terms, your contribution base is the amount used to calculate social security contributions.

What is the contribution base?

The contribution base (base de cotización in Spanish) is basically the amount of money used to work out how much you pay into your social security contributions. In Spain, contributions can go up or down and these variations are calculated on the basis of the contribution base.

Both self-employed workers and employees have their own contribution base, and everyone pays a monthly percentage to contribute and receive social benefits.

Self-employed workers contribute through the self-employed contribution, while employees do so through their companies.

The contribution base for self-employed workers in Spain

While for salaried workers the contribution base is linked to their gross salary (a percentage of their salary goes directly towards paying social security) self-employed workers have some flexibility on this due to recent reforms and the unpredictability of being freelance or owning your own business.

According to experts TaxScouts.es, in Spain the self-employed “can more or less choose the contribution base they want.”

While employees only pay around 6 percent of their salary for social security (the rest is paid by the company) the self-employed have to pay the full percentage. This means that self-employed workers pay around 31 percent of their chosen contribution base to Social Security every month.

How is the contribution base for the self-employed in Spain calculated?

This is where things get a little complicated. Until 2023, self-employed workers in Spain could choose how much they wanted to contribute regardless of their income.

However, from January 2023, this changed, and each self-employed worker is now given a contribution base corresponding to their net income. The Social Security system has created contribution brackets in which, for each bracket of net monthly income, a minimum and maximum contribution base is assigned.

This way, self-employed workers can choose which base they want to contribute, but always within their income bracket.

What are Spain's contribution bases?

According to PricewaterhouseCoopers: "The minimum contribution for the lower bracket is set at €653.59, while the maximum contribution in the upper bracket is set at €4,909.50.

Social security benefits would depend on the contributions paid by the self-employed, the general rate being 31.4 percent which is applied on a monthly social security contribution base chosen by the self-employed."

The following table with data from Spain's Social Security Department shows the minimum contribution base in 2025 for each monthly earnings bracket and what it equates to in monthly social security fees.

In other words, the smallest amount you can pay in social security taxes each month depending on your estimated earnings bracket.

The table does not include the maximum contribution bases for each category, so it is aimed at self-employed workers who want to pay less.

Estimated net monthly earning brackets	Minimum contribution base in 2025	Monthly fee in 2025
Up to €670	€653.59	200 €
Between €670 and €900	€718.95	220 €
Between €900 and €1,125.90	€849.67	260 €
Between €1,125.90 and €1,300	€950.98	280 €
Between €1,300 and €1,500	€960.78	294 €
Between €1,500 and €1,700	€960.78	294 €
Between €1,700 and €1,850	€1,143.79	350 €
Between €1,850 and €2,030	€1,209.15	370 €
Between €2,030 and €2,760	€1,274.51	390 €
Between €2,330 and €2,760	€1,356.21	415 €
Between €2,760 and €3,190	€1,437.91	465 €
Between €3,190 and €3,620	€1,519.61	490 €
Between €3,620 and €4,050	€1,601.31	515 €
Between €4,050 and €6,000	€1,732.03	530 €
€6,000 or more	€1,928.10	590 €

Choosing your contribution base

Due to the reforms made in 2023, as a self-employed worker you are required to report your net monthly income to Social Security and your contributions are based on this amount.

Within your income bracket, you can choose whether you prefer to pay the minimum or maximum contribution. According to Tax Scouts, over 80 percent of self-employed workers in Spain choose the minimum contribution base.

To choose your base, all you have to do is estimate your income first, and once you have your income bracket, inform Social Security of your chosen contribution base.

This can be done through the Importass portal on the Social Security site, but many foreigners in Spain hire a gestor or accountant to handle it for them. You will need your certificado electrónico or Clave to access the Social Security portal. You can head directly to the section on contribution bases and see the contributions you have made up to now here.

Which base should I choose?

When choosing your contribution base, it is important to bear in mind that if you choose the minimum contribution base for your income bracket, you will pay less each month. However, when you receive benefits (such as sick leave or a pension) the amount you get will be lower.

On the other hand, if you choose the maximum, you will pay more each month but you will receive better benefits when you need them.

If you are able to generate a lot of money, you may be able to choose a higher contribution base, because that means you will have better benefits in the long run.

Another factor to consider is that if your business or sector is unpredictable and income varies greatly from month to month, if you choose a high contribution base, there may be months when you cannot afford to pay your Social Security contributions.

Can I change my base?

Yes, you can. It's up to you to inform Social Security of your predicted earnings, so they know how much to charge you. You can change this contribution base up to six times per year as your earnings increase and decrease, meaning that you may not always be paying the same amount each month.

Self-employed workers in Spain pay some of the highest social security contributions in Europe, however, they also receive some of the greatest benefits. Health care, sick pay, maternity and paternity benefits and pensions are all available to self-employed workers here.

This is not the case in many other European countries, who may have to pay extra for health insurance or do not get any maternity or paternity benefits if they’re self-employed.

Our journalists at The Local are not tax experts. This article is meant to be informative but it’s always advisable to consult a gestor or accountant before making financial decisions.