Permanent Establishment in Spain: When Non-Resident Companies Trigger Spanish Tax.

Why the tax question often arises before a branch or subsidiary is formally created.

Many foreign companies approach Spain as a commercial market first and a tax jurisdiction later. That sequence is understandable, but it can be expensive. In practice, a company may create a taxable presence in Spain long before it sets up a Spanish subsidiary or registers a branch. Under Spain’s Non-Resident Income Tax rules, a non-resident entity is considered to operate through a permanent establishment when it has a continuous or habitual place of business in Spain where all or part of its activity is carried on, or when it acts in Spain through an agent with authority to conclude contracts on its behalf. Spanish law expressly includes, among other examples, places of management, branches, offices, factories, workshops, warehouses and construction or installation works lasting more than six months.
That is why the issue of a presence in Spain that may be considered a permanent establishment should be reviewed as a decision issue, not as a compliance afterthought. Once a permanent establishment exists, the foreign company moves into a different Spanish tax framework. Under Spanish tax rules, non-residents operating through a permanent establishment are taxed in Spain on the income attributable to that permanent establishment. The taxable base of the permanent establishment is determined broadly under the general rules of Spanish Corporate Income Tax, and the permanent establishment must keep separate accounting and comply with formal obligations comparable to those of Corporate Income Tax taxpayers.

Permanent establishment is not the same as a branch or a subsidiary.

This distinction is essential. A branch is a corporate and registration decision. A subsidiary is a separate legal entity. A permanent establishment, by contrast, is a tax concept. AEAT states expressly that a permanent establishment does not have separate legal personality from its head office. In other words, the Spanish tax analysis can arise even where the business has not yet formalised its local presence through a branch or a company.
This is exactly why the article should be read together with our guide on Branch vs. Subsidiary in Spain. The legal structure and the tax footprint are related, but they are not the same question. A company can decide not to register a branch and still face a Spanish permanent establishment issue if the factual pattern points in that direction. That is an inference drawn from the Spanish definition of permanent establishment and the fact that branches and permanent establishments are not conceptually identical.

The first question: does a treaty apply?

Before applying Spanish domestic law in isolation, the company should ask whether there is a double tax treaty between Spain and its country of residence. AEAT’s own census guidance makes this point clearly: if a treaty exists, the definition of permanent establishment is the one contained in that treaty; only if no treaty applies should the domestic Spanish definition be used on its own. AEAT also notes that treaties generally follow the OECD model, under which a permanent establishment is a fixed place of business through which the enterprise carries on all or part of its business.
That matters because the answer is not always the same under domestic law and under a treaty. Spanish domestic law includes construction, installation or assembly works lasting more than six months as permanent establishments. By contrast, the OECD-style treaty language reproduced by AEAT states that a construction or installation project generally becomes a permanent establishment only if it lasts more than twelve months. The practical conclusion is straightforward: companies should not assume that the domestic threshold is always the final one if a treaty is in force.
For the broader treaty framework behind this analysis, see our article on Double Taxation Relief: How to Apply International Treaties for Business Income in Spain. If your group has a UK connection, the same logic should also be read alongside our post on the Spain–UK Double Taxation Agreement.

Three situations that deserve special attention.

Warehouses and logistics.

Warehousing is one of the most misunderstood areas in cross-border tax planning. Spanish domestic law expressly includes warehouses among the examples of permanent establishment. However, the treaty pattern reproduced by AEAT also states that a fixed place used only for storage, display or delivery of goods may fall outside the permanent establishment definition if the activity remains merely preparatory or auxiliary.
This is where many foreign companies underestimate the issue. A warehouse used purely for limited logistical support may not carry the same risk as a warehouse that is integrated into a broader Spanish commercial operation. Once warehousing is combined with local personnel, operational decision-making, customer-facing activity or a more substantive part of the business cycle, the analysis becomes more serious. The key point is not whether the business calls the facility “just logistics”, but whether the activity in Spain still looks genuinely auxiliary when examined against the treaty and the actual operating model. That last sentence is an inference from the treaty pattern AEAT reproduces and should be assessed case by case.

Construction or installation projects.

This is one of the clearest permanent establishment risk areas because the law itself gives a duration test. Under Spanish domestic law, construction, installation or assembly works lasting more than six months are expressly listed as permanent establishments. Under many treaties, including OECD-style language, the threshold is often more than twelve months.
For groups carrying out projects in Spain, this means the tax review should happen before the project becomes established operationally. Once the timeline, site organisation, subcontracting structure and local presence are already in motion, it is often too late to treat the matter as a minor filing issue. What looks like a temporary project from an operational perspective may already be moving into Spanish taxable territory from a tax perspective.

Directors managing from Spain.

Management activity in Spain is another area that deserves attention, especially because Spanish law expressly includes places of management among the examples of permanent establishment.

This matters in two ways. First, where strategic or operational management is effectively carried out from Spain on a sustained basis, the company may need to assess whether it has created a Spanish taxable presence. Second, in more serious cases, the discussion may go beyond permanent establishment and move into corporate tax residence, because entities whose place of effective management is in Spain can be treated as Spanish tax residents and taxed on their worldwide income.
That does not mean every director visiting Spain creates a permanent establishment or changes the company’s residence. It does mean that management performed from Spain should never be treated as irrelevant simply because the company is incorporated elsewhere. The tax review should focus on substance, continuity and where key decisions are genuinely being taken.

Why this matters commercially.

The real risk is not only additional tax. It is also timing, governance and credibility. A company that discovers the permanent establishment issue late may face hurried compliance, poorly prepared documentation and a weak position if the tax treatment is challenged. By contrast, a company that reviews the issue early can decide whether to keep the activity below the permanent establishment threshold, formalise a local structure deliberately, or adapt the operating model before Spanish tax is triggered.
For a practical overview of the corporate tax consequences once a Spanish taxable footprint exists, see our service page on Corporate Income Tax in Spain.

Conclusion.

A company does not need to open a Spanish subsidiary or register a branch before Spanish tax becomes relevant. In many cases, the more important question is whether its facts on the ground already amount to a permanent establishment. Warehouses, installation projects and management carried out from Spain are three areas where that risk deserves early review. The legal test may look simple, but its application depends on the interaction between Spanish domestic law, treaty protection and the real substance of the activity in Spain.