What to Check Before Starting Work in Spain? REA, Posted Workers, VAT and Required Formalities
Lawants Guide · Installation Work and Foreign ContractorsThe contract is signed, the installation date cannot be postponed, and the technicians are ready to leave for Spain. This is often the exact moment when the client, the main contractor, or the site manager asks for the REA certificate as a condition for site access and for the start of the works.
For a foreign company that does not usually work in the construction sector, the request can arrive unexpectedly, often when there is little room left to act. Before entering the site, however, it is necessary to make sure that not only REA registration but also the other documents and requirements for the activity, the staff being sent and the specific project are ready.
In this guide, Lawants sets out what needs to be in place before sending technicians and installers to Spain: from the REA procedure to health and safety training, from posted-worker notifications to site-specific obligations, through to VAT treatment and permanent establishment risk. The goal is to coordinate every check and complete the paperwork without putting the planned start date at risk.
Can a Foreign Company Install Equipment in Spain Without Setting Up a Company?
In most cases, yes. For REA registration, a foreign company does not need to set up a Spanish company, open a subsidiary or a branch, or obtain a Spanish non-resident NIF beforehand (the one starting with the letter N). Anyone who says otherwise is confusing REA requirements with other formalities.
This does not mean the structure is irrelevant. Before starting works, the operation should be assessed from a tax perspective: duration of the site, permanent establishment risk, VAT, relationship with the client. In some cases, though not all, operating through a Spanish company, a subsidiary or a branch turns out to be the most efficient solution.
The real question to answer is which specific requirements apply to that particular project.
When the site start date is approaching, the check is usually triggered by a specific request: the client asks for the REA certificate, the main contractor asks for posted-worker documentation, or access to the site is made conditional on presenting certain documents.
If the project is still at the planning stage, the same analysis makes it possible to organise the assignment of staff in advance and prevent operational bottlenecks.
There are commonly four areas to examine:
- Registration with the Registro de Empresas Acreditadas (REA) concerns certain activities carried out as part of construction works or civil engineering projects, when the company acts as a contractor or subcontractor.
- The posted-worker notification concerns the temporary assignment to Spain of employees of the foreign company.
- The VAT place of supply determines the tax treatment of the supply, and can become particularly relevant when the sale includes assembly or installation in Spain.
- The risk of permanent establishment depends on the duration, nature and execution of the project, including any preparatory activities, in light of the applicable double taxation treaty.
These areas can overlap, but they rest on different conditions. Being asked for the REA certificate does not automatically mean VAT registration is required, just as sending workers to Spain does not, on its own, create a permanent establishment.
The most common mistake is to start from the single document requested by the client and treat it as proof that every other requirement applies as well. The assessment should instead look separately at the activity carried out, the contractual role, the staff being sent, and the location and duration of the project.
Factors That Determine REA, VAT, Posted Workers and Permanent Establishment: Operational Checklist
Many companies contact us when they already have installation or other site work scheduled in Spain, and need to quickly clarify two things: whether REA registration is required, and whether the project calls for Spanish VAT registration.
There is no single answer that applies to every project. The requirements that apply depend on a combination of variables: the activity carried out, the company’s role under the contract, staff being posted to Spain, and the location and duration of the works. This analysis can lead to distinct obligations, such as registration with the Registro de Empresas Acreditadas, a posted-worker notification, the VAT place of supply, or a permanent establishment.
To understand which requirements and documents are actually needed before entering the site, it helps to start from five questions. Here they are, along with what each answer can lead to.
| Question About the Project | Why It Matters | Potential Requirement |
|---|---|---|
| Where do the works take place? | Determines the authority and procedure | REA forms, posting, local requirements |
| What is the actual activity? | Defines the scope of the works | Possible REA and permits |
| What is the contractual role? | Distinguishes supply, contracting and subcontracting | REA, Libro de Subcontratación, VAT |
| Who is being sent? | Identifies staff and duties | Posting, A1 certificate, training |
| How long does the project last, and how is it organised? | Affects tax presence | Possible permanent establishment |
When Is REA Required to Install Equipment in Spain?
Many foreign companies find out about REA not through a notice from the Spanish authorities, but directly from the client, the main contractor, or the site manager. The request often comes once the contract is already signed, the technicians are ready to travel, and site access is made conditional on presenting the certificate.
The Registro de Empresas Acreditadas is not a general authorisation to work in Spain, nor a technical certification of the equipment itself. It is the register through which companies acting as contractors or subcontractors on certain works confirm that they have their own productive organisation, adequately trained staff, and a compliant risk-prevention system.
REA originates in Spanish legislation on subcontracting in the construction sector. Its scope, however, does not depend only on the sector the company identifies with or its declared activity code. Even an equipment manufacturer or an industrial supplier can fall within its scope when it sends its own technicians to carry out work that forms part of a construction or civil engineering project.
This is why a company that does not consider itself part of “construction” can still receive a registration request: what counts is the work actually carried out in Spain, the context of the project, and the contractual role taken on. A request from the client or main contractor is therefore the signal that a check is needed straight away, but it does not by itself prove that REA registration is legally required.
For more detail, read our complete guide to REA registration in Spain.
Foreign Company or Local Structure: What Changes for REA
Operating in Spain as a foreign company, without a local structure, does not mean operating irregularly: it is one of the most common configurations for temporary installation projects, and REA registration can be requested directly by the foreign company.
Anyone considering setting up a Spanish company, a subsidiary or a branch in order to obtain REA registration should know that a local structure does not make the procedure any simpler. Subsidiaries and branches are subject to exactly the same requirements as any Spanish company: its own productive organisation, staff, prior training and preventive organisation.
The choice of structure should therefore be made for tax, contractual and market-presence reasons, not because of REA.
Which Activities Fall Under the REA Requirement
Ley 32/2006 and Real Decreto 1109/2007 cover contracting and subcontracting agreements relating to the following activities:
- Excavation
- Earthmoving
- Construction
- Assembly and disassembly of prefabricated elements
- Fitting-out or installation works
- Conversion
- Refurbishment
- Repair
- Dismantling
- Demolition
- Maintenance
- Upkeep, painting and cleaning works
- Drainage and sanitation works
The fact that terms such as “installation”, “repair” or “maintenance” appear on this list does not make registration mandatory for every intervention. Simply selling, delivering, or supervising a piece of equipment does not necessarily amount to an activity subject to REA.
The position can be different where the company sends its own workers to assemble, anchor, connect, or permanently integrate the equipment into the works.
To determine whether a foreign company needs to register, three elements have to be checked together:
- Is the work carried out as part of a construction or civil engineering project?
- What activity do the technicians actually carry out on site, and does it fall within the works covered by the legislation?
- Does the company act as a contractor or as a subcontractor in the project?
Health and Safety Training and Preventive Organisation: What to Document for REA
The legislation requires that, already at the time of the REA application, the prior training of managerial and operational staff and an adequate preventive organisation are documented.
One of the most common mistakes is assuming the REA application can be filed first and health and safety training completed afterwards. In reality, at the time of the application the company must already be able to show that both staff with managerial duties and the workers assigned to the site have completed the required occupational risk-prevention training through a Servicio de Prevención Ajeno (SPA), an external risk-prevention service, and that the company has an adequate preventive organisation.
This is not, therefore, a formality to be sorted out after registration. The certificates and supporting documentation must be available and usable within the procedure: if the training has not been completed or is not properly documented, the application cannot proceed and site access risks being postponed.
The REA application cannot be filed with health and safety training to be completed later. At the time of filing, the managerial and operational staff assigned to the site must already be trained, and the relevant certificates must be available.
We coordinate the Servicio de Prevención Ajeno, the mandatory staff training, and the collection of certificates. Before the application is filed, we check that the preventive organisation and the required documentation are complete and usable in the procedure.
Eight-Day Exemption from REA Registration and Posted-Worker Notification
For ordinary postings covered by Article 2(1)(1)(a) and (b) of Ley 45/1999, the posted-worker notification is not required where the posting does not exceed eight days, the eighth day included (Article 5(3)). The First Additional Provision (letter b) of Real Decreto 1109/2007 provides a similar exemption for REA registration, but it only concerns companies within the scope of that decree, that is, those acting as contractors or subcontractors on construction works.
The exemption does not apply in the same way to temporary work agencies, and above all it does not remove the other obligations linked to the project: workplace safety, social security, working conditions, site access and any immigration-related aspects still need to be checked, regardless of how short the posting is.
Notification of the Opening of the Workplace (Centro de Trabajo) and the Libro de Subcontratación
On works falling within the scope of construction legislation, the notification opening the Centro de Trabajo (workplace) must be filed before works begin, by the party acting as contratista.
Each contratista must also keep a Libro de Subcontratación on site, recording every subcontracting arrangement, regardless of how many tiers are involved.
This follows from article 8 of Ley 32/2006 and article 19 of Real Decreto 1627/1997.
REA registration obtained within 72 hours for a British company operating in Madrid
Lawants correctly separated REA registration from the NIF process, removing unnecessary steps and unlocking operational site access within a very short timeframe.
A British company specialising in temporary structures and industrial installations had secured a contract for a major international event in Madrid. It was operating in Spain for the first time, with no local structure in place.
The client believed a Spanish NIF had to be obtained first in order to register with REA. With a non-negotiable site schedule, this would have caused weeks of delay.
Immediate procedural diagnosis: the NIF was not an automatic prerequisite for REA registration.
REA application prepared and handled entirely remotely, without apostilles, notarial deeds or translations that are not required.
Parallel coordination with the Servicio de Prevención Ajeno, so occupational risk-prevention training did not become a bottleneck.
“The point was not just to obtain REA registration quickly, but to understand which requirements were genuinely necessary and which were unnecessarily slowing the client’s operations down.”
When REA, NIF and compliance are handled in the wrong order, the risk is not merely administrative: it is operational. Lawants coordinates every requirement in a single workflow, avoiding delays and unnecessary requests.
Contact Lawants →Installation and Assembly Work in Spain: Common Mistakes Foreign Companies Make
In our experience, most delays do not come from particularly complex legislation, but from a handful of incorrect assumptions that come up consistently among foreign companies preparing to work on a site in Spain for the first time.
- Waiting for a Spanish NIF that is not actually needed: this is the most common bottleneck we see. The NIF is not, in itself, a condition for REA registration.
- Filing the application without complete preliminary documentation: training and preventive organisation must already be documented at the time of the application, not still in progress.
- Confusing REA registration with the posted-worker notification: these are two separate procedures, handled by different authorities, with partly different documentation; completing one does not mean the other has been dealt with.
- Assuming the eight-day exception removes every obligation: the exception applies specifically to the posted-worker notification and REA registration, not to safety, social security or other related requirements.
- Counting duration by looking only at assembly days: site visits and preparatory work can affect how presence in Spain is calculated, but their relevance needs to be checked case by case, not assumed automatically.
Site access date already set? Lawants obtains your REA registration in 72 hours, without waiting for a Spanish NIF.
We check straight away whether your company meets the requirements and holds the documents needed to file the REA application, flagging any gap before submission so it does not block the process. If you are waiting on a Spanish NIF, we check whether it is actually needed in your case.
REA registration within 72 hours of receiving and validating the complete documentation, with a full fee refund if the deadline is missed.
Managing Director, Lawants
Response within 24 business hours
Other Aspects to Check: Posted Workers, VAT, Permits and Permanent Establishment Risk
REA registration is only one of the checks required for an installation project in Spain. Sending staff, VAT treatment, any technical permits, and the length of the company’s presence all need to be assessed separately, since they can create obligations even when REA does not apply.
Posting Workers: Mandatory Documents for Technicians and Installers
If the foreign company sends its own employees to work on the Spanish site, the rules on posting workers to Spain apply, regardless of REA and VAT status. The main requirements include submitting a prior notification to the competent labour authority, appointing a representative in Spain, and keeping documentation on working hours, pay and working conditions for the period required by the legislation. For postings from the EU, EEA or Switzerland, each worker should hold a Portable Document A1 where the social security legislation of the home country continues to apply. Different rules apply to workers posted from countries outside these areas.
VAT Place of Supply for Installation and Assembly Work in Spain
The supply of goods that includes installation or assembly follows a different territoriality rule from a straightforward intra-EU or cross-border sale. As a general principle, the transaction is considered to take place in Spain when the installation is completed before the goods are made available, is finished on Spanish territory, and results in the goods being permanently fixed (Ley 37/1992, art. 68).
This criterion determines where the transaction is deemed to take place, not who must account for the VAT. Being located in Spain for VAT purposes does not automatically mean the foreign company must register for VAT there, nor that Spanish VAT must be charged directly on the invoice: the reverse charge mechanism (art. 84 Ley 37/1992) can apply, but whether it does depends on several factors, not on the client’s VAT registration in Spain alone, including whether the supplier is already established in Spain or has a permanent establishment involved in the transaction, whether the recipient is genuinely acting as a business, the exact nature of the transaction, and any exceptions set out in the legislation.
This is one of the areas that requires a case-by-case assessment.
Technical Permits and Regional Requirements for Installation Work in Spain
Some installations require formal recognition of the technicians’ professional qualifications by the competent bodies of the relevant Comunidad Autónoma, in addition to compliance with the applicable Spanish technical standards, such as the Reglamento Electrotécnico para Baja Tensión (REBT) for electrical installations.
This is a specific technical area that needs a dedicated check depending on the type of equipment involved.
Permanent Establishment in Spain: When a Site Becomes a Tax Risk
Under many double taxation treaties signed by Spain, a construction or installation project may create a permanent establishment once the treaty-specific duration threshold is exceeded. Under the Spain-UK treaty, for example, the threshold is twelve months, while other treaties may provide for a shorter period. Once a permanent establishment arises, the consequences go beyond the specific transaction: local tax registration, separate accounting and taxation of the income generated in Spain.
Certain preparatory activities carried out in Spain and directly linked to the project, such as site visits or site preparation, can also affect how the duration is calculated: their relevance needs to be checked against how the project is actually organised, not assumed automatically.
It is also worth remembering that the duration threshold applies specifically to the construction or installation project itself: a permanent establishment can also arise from other grounds, such as a stable fixed place of business in Spain, independently of how long the site lasts.
Documents to Prepare Before Technicians and Installers Travel to Spain
Before technicians and installers reach the site, it is advisable to have the baseline documentation ready: the documents Spanish authorities and clients request most often, regardless of the outcome of the assessment of the four areas described above.
The essential documents to check before departure
- Up-to-date company registration extract for the foreign company
- Tax details required by the applicable regional form
- Training and preventive organisation already documented
- Portable A1 certificate for each worker (where applicable)
- Identification details and role on site
- Contract or engagement letter for the activity in Spain
- Location, dates, activity and contractual role in the project
Operational priority: occupational risk-prevention training and A1 certificates should not be left until the last few days. Missing them can block the application or prevent workers from accessing the site.
This list does not replace the assessment of REA, posted workers, VAT and permanent establishment: it is the baseline documentation common to most temporary installation projects in Spain.
Lawants Method: How We Obtain REA Registration in 72 Hours
From the first check to registration, with a single point of contact
The 72-hour period runs from receipt of the complete documentation required for the specific case.
We handle the procedure without requesting a Spanish NIF beforehand and, in the cases handled through our process, without notarial deeds, legalisations, sworn translations or apostilles. We send the client a document listing the information required; once it is received, we complete the procedure within 72 hours.
- Checks before filing: we review requirements, training and documentation before the application is submitted, reducing the risk of requests for further information that would stall the process.
- Only the necessary steps: we avoid obtaining a Spanish NIF in advance and unnecessary formalities whenever the case can be handled through the process dedicated to foreign companies.
- Guaranteed deadline: the 72 hours are a contractual guarantee. If the deadline is missed, the fee is refunded in full.
The guarantee is contractual: if we do not meet the 72-hour deadline from receipt of the complete documentation, we refund the fee in full. Across the engagements we have handled so far, this guarantee has never been triggered, which we treat as proof of the process, not as a commercial promise. For companies with contractually binding assembly dates that cannot slip, this is often the deciding factor in choosing to work with us.
Fixed start date in Spain? Lawants handles REA, posted workers and tax through a single point of contact.
We assist foreign companies that need to operate temporarily in Spain without setting up a local structure, coordinating REA, tax and employment matters through a single point of contact. We do not close the file the day registration is granted: we remain available for the related requirements that come up as the project moves forward.
Frequently Asked Questions About Installation and Assembly Work in Spain
Answers to the questions we receive most often from foreign companies that need to install or assemble equipment in Spain.
Do I need a Spanish NIF to register with REA?
No, a foreign company does not necessarily need to obtain a Spanish NIF beforehand. The application does include the company’s tax identification details, which must be provided under the applicable procedure. This is one of the most common mistakes we see, often carried over from procedures designed for other, unrelated requirements.
How long does it take to obtain REA registration?
It depends on how complete the submitted documentation is, particularly the documents relating to training and preventive organisation. With complete documentation, Lawants obtains registration within 72 hours.
Who has to submit the posted-worker notification?
Any company that sends its own employees to work temporarily in Spain as part of a service, regardless of whether REA or VAT registration applies. Specific exemptions can apply to postings of no more than eight days.
What happens if the project runs longer than 12 months?
A construction or installation project that exceeds the duration threshold set out in the applicable double taxation treaty, commonly twelve months, can create a permanent establishment. It is worth checking this risk well before the project approaches the threshold, taking into account any preparatory activities directly linked to the works.
Do I need to set up a company to install equipment in Spain?
In most cases, no. A foreign company can operate directly, without a branch or a local company. Setting up a structure in Spain depends on other factors, such as the ongoing nature of the project or requirements linked to subcontracting.
Is REA registration enough to access the site?
Not on its own. Depending on the project, you may also need the posted-worker notification, the A1 certificate for staff, the opening of the centro de trabajo, and any specific requirements set by the venue or the client.
