What to Check Before Posting Workers to Spain: Notification, A1 Certificate and REA
Lawants Guide · Posting Workers to SpainA contract already signed for work in Spain, an intra-group assignment or a technician scheduled to carry out a two-week installation: these are different scenarios, but they raise the same operational question. What must the company do before the assignment begins?
Posting workers to Spain triggers three separate requirements that companies frequently treat as one: the posted worker notification to the labour authority, the A1 certificate for social security, and, in construction, registration with the Registro de Empresas Acreditadas (REA). None of these substitutes for the others. Missing one, or completing it late, can block site access, trigger inspections and result in fines that scale with the severity of the breach.
This guide covers when a posting to Spain actually arises, how to notify it through the LEY45 portal, when the eight-day exemption applies, what the A1 certificate and social security coordination involve, working conditions to guarantee, long-term postings beyond 12 months, construction and transport rules, and current sanctions.
When Does Sending an Employee to Spain Count as a Posting?
Sending employees abroad does not automatically qualify as a posting, and not every business trip to Spain triggers the same obligations.
Before considering the advance notification, A1 certificate or REA registration, the company should carry out two preliminary checks: whether the assignment falls within the posting rules and, if so, which requirements apply.
Spanish Posting Rules
Under Law 45/1999, which transposes EU Directive 96/71/EC, a transnational posting to Spain arises when a company established in an EU or EEA Member State temporarily sends a worker to Spain, while the employment relationship remains in the home country, in one of the following cases:
- Contract-based posting: the worker operates on behalf of and under the direction of their employer, under a contract concluded between that company and a recipient established or operating in Spain.
- Intra-corporate posting: the worker is assigned to a workplace of the same company or of another company within the same group, located in Spain.
- Temporary work agency posting: a temporary employment agency based outside Spain assigns a worker to a user company established or operating in Spanish territory.
Business Trip or Posted Worker? Where the Line Is Drawn
Not every visit to Spain constitutes a posting. The key question is whether the employee will carry out work in Spain as part of a cross-border service, including for a client, another group company or a user undertaking. Attendance at meetings, conferences, trade fairs or training that does not involve performing such work will generally fall outside the posting regime: the European Commission’s Practical Guide on Posting of Workers (2019) confirms that such business trips are exempt from the administrative requirements under Article 9 of Directive 2014/67/EU.
The assessment depends on the activity actually carried out, not simply on the duration or label of the trip: an employee attending a trade fair in Madrid requires no notification; a technician sent to install equipment for a Spanish client does, even for a few days. The underlying EU framework is shared when posting workers to Europe more broadly, but notification procedures, exemptions and documentation requirements vary between Member States and must be checked separately.
Not every trip to Spain is a posting. But getting the assessment wrong can compromise every requirement that follows.
The assessment depends on the activity actually carried out, the relationship with the Spanish recipient, and how the worker is sent. Lawants reviews the project before departure, identifies the applicable rules, and confirms which requirements must be completed to operate correctly in Spain.
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Requirements for Posting Workers to Spain: Notification, A1 Certificate and REA
Once a transnational posting is confirmed, the company does not complete a single formality. It must check three separate requirements: the posted worker notification to the labour authority, the A1 certificate for social security, and, only when the construction-sector conditions apply, REA registration.
Not every posting triggers all three. But completing one does not satisfy the others: each serves a different purpose, involves a different authority, and follows its own conditions for applying.
| Requirement | What it does | When to check it |
|---|---|---|
| Posted worker notification (LEY45) | Informs the Spanish labour authority of the posting | Before the posting begins |
| A1 certificate | Confirms which social security system applies | Before departure, whenever possible |
| REA registration | Demonstrates specific requirements for construction work | Before being contracted or subcontracted, where applicable |
Operational Checklist for Posting Workers to Spain
If the activity in Spain already has a start date, it helps to work through these requirements in sequence. These are the four phases to manage before and during the posting.
Assess the case
Confirm the activity, duration and location of the work.
Prepare the requirements
Notification, local representative, A1 certificate and REA where applicable.
Before departure
Check documentation and applicable working conditions.
During the posting
Keep documentation available and manage any changes.
Posted Worker Notification: How to Notify the Spanish Labour Authority
The posted worker notification is the central requirement when posting workers to Spain. Every company within the scope of Law 45/1999 must notify the labour authority of the Autonomous Community where the services will be provided, regardless of the posting’s duration, except where an exemption applies.
When to Submit the Posted Worker Notification
Article 5 of Law 45/1999 requires the notification to be submitted before the posting begins. The law does not set a fixed lead time, such as one day in advance: it simply requires that the notification precede the actual start of the activity in Spain. In practice, submitting it a few days ahead of time reduces the risk of delays caused by formal errors or missing data.
Eight-Day Exemption: When It Applies and When It Doesn’t
For postings falling under Article 2.1.1, letters a) and b), of Law 45/1999 (contract-based and intra-corporate postings), the notification is not required when the duration does not exceed eight days. This wording covers a posting of exactly eight days, not only postings shorter than that.
Article 5.3 does not provide for an indiscriminate accumulation of every posting a company carries out in Spain over a given period. The succession or replacement of workers within the same service does, however, need to be assessed carefully, in light of the duration criteria set out in Article 3.
The eight-day exemption never applies to temporary work agencies: for these, notification is mandatory from the first day of the posting.
An exemption from the posted worker notification does not automatically remove the other requirements. The A1 certificate, working conditions, documentation, and any construction-sector obligations still need to be checked.
What Information the Posting Notification Must Include
The notification must contain:
- Company identification, tax address and VAT registration number
- Personal and professional details of the posted workers
- Identification of the company or workplace where services will be provided
- Planned start date and duration of the posting
- Description of the services to be provided, indicating the relevant case under Article 2.1.1
- Contact details of the local representative present in Spain
- Contact details of the person authorised to take part in worker information and consultation procedures
Temporary work agencies must also include accreditation issued by their home State and a declaration from the Spanish user company on its temporary need for workers.
Appointing the Local Representative for Posted Workers to Spain
Law 45/1999 requires the company to designate, within the notification, a natural or legal person present in Spain, without requiring tax residence or domicile, sufficient to ensure a link with the competent authorities.
The notification actually distinguishes two separate roles, often collapsed into a single “domiciled representative” by imprecise guides:
- Liaison with the Spanish authorities: receives and sends official documents and notifications on the company’s behalf, and is the point of contact for the Labour Inspectorate.
- Person for worker information and consultation procedures: represents the company in negotiation procedures affecting posted workers, a distinct role that in practice can be held by the same person.
In our experience, appointing a professional with specific expertise in Spanish labour law for this role reduces the risk of errors in the notification and makes inspections easier to manage.
The LEY45 Portal: How to Notify Postings to Spain Online
Spain’s Ministry of Labour and Social Economy, through the State Labour Inspectorate body (OEITSS), operates the LEY45 Portal, the central register for transnational posting notifications. Companies submit the notification electronically in a single format, regardless of which Autonomous Community will host the activity. Notifying through this portal does not replace any other notification obligation under separate regulations, which still applies in addition.
A1 Certificate and Social Security for Posted Workers to Spain
The A1 certificate concerns social security, not the labour authority. For workers subject to the EU, EEA, Swiss and, depending on the case, UK social security coordination rules, the employer requests it from the home country’s social security institution, whenever possible before the posting starts. For postings from other countries, coverage needs to be checked case by case against the applicable bilateral agreement.
The certificate confirms that the worker remains covered by the home country’s social security system under EC Regulation 883/2004, preventing double contributions. Posted-worker social security coverage normally runs for up to 24 months, extendable in specific cases. Without an A1 certificate, Spanish authorities may require registration in the Spanish social security system, with back-payments and penalties for the company.
Companies should also verify how the worker will access healthcare in Spain. For short stays that do not involve transferring residence, the European Health Insurance Card may be sufficient. The Portable Document S1 may instead be required when the worker resides in Spain during the assignment while remaining insured under the home-country system. The appropriate document depends on the worker’s circumstances and the expected duration of the stay. Full details are available through Spain’s official Punto de Acceso General.
A1, notification and REA are not the same file: completing one does not rule out the others.
Before sending staff to Spain, you need to confirm the applicable social security system, request the certificate from the competent authority in the home country, and coordinate this step with any labour and sector-specific obligations. Lawants reviews the actual case and organises the requirements before the activity starts.
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Minimum Working Conditions for Posted Workers in Spain
Regardless of the law governing the employment contract, the company must guarantee posted workers in Spain the conditions set out under Spanish labour law for a specific set of matters.
Working Hours, Rest Periods and Leave for Posted Workers
These include maximum working hours, a minimum rest period of 12 hours between working days, weekly rest, night and shift work rules, and paid annual leave, set by the Spanish Workers’ Statute at a minimum of 30 calendar days a year. For postings not exceeding eight days, carried out by companies other than temporary work agencies, the annual leave rules do not apply.
Minimum Wage and Pay for Posted Workers in Spain
The baseline reference is the Spanish minimum interprofessional wage, set by Royal Decree 126/2026 at €40.70 per day or €1,221 per month, equal to €17,094 a year for a full-time position. The same eight-day exception applies to pay under Article 4 of Law 45/1999.
Relying on this national figure alone is often not enough. The minimum wage is the statutory floor, but the reference that most often determines the actual pay owed is the collective bargaining agreement applicable to the place and sector where the work is carried out, which can set higher amounts.
Applicable Collective Bargaining Agreement
Spanish collective agreements (convenios colectivos) apply based on the nature of the work performed and the place where it is carried out, not the employer’s country of origin. Identifying the right agreement requires checking the Register of Collective Agreements (REGCON) for the relevant province and sector, since pay and working-time terms can vary significantly between sectors.
Posting Allowances and Expense Reimbursements
Allowances linked to the posting, such as travel, meal and accommodation reimbursements, are not treated as part of pay for minimum wage purposes, to the extent they cover expenses actually incurred because of the posting. Where the employment contract or applicable agreements do not specify whether part of an allowance is expense reimbursement or pay, the entire allowance is treated as reimbursement.
Documents to Keep When Posting Workers to Spain
During the posting, the company must keep available, at the workplace or in digital format, the documents that demonstrate compliance. Article 6 of Law 45/1999 does not set a single fixed retention period for all documentation: the law requires that documents be available for immediate consultation during the posting, and that the company remain able to produce them if the Labour Inspectorate requests them after the assignment ends.
- Employment contracts or equivalent documents evidencing the employment relationship
- Payslips and proof of payment, demonstrating compliance with the applicable minimum pay
- Time records showing the start, end and duration of each working day
- Work authorisations for non-EU nationals, under the home country’s legislation
- Spanish translation, or translation into the co-official language of the relevant territory, required when documents are presented to the authority
On the translation point specifically: employment contracts and other required documents do not need to be pre-translated and stored in Spanish for the entire posting by default. Translation is required when the documentation is actually presented to the Spanish authorities, into Spanish or the co-official language of the territory where the services are provided.
Posting Workers to Spain: Cases That Require Further Checks
Most postings fall squarely within the standard rules covered so far. A smaller number of cases add a further layer: postings that run past 12 months, work on a construction site in Spain, staffing through a temporary agency, road transport, and postings involving UK or non-EU nationals. Each of these needs an extra check on top of the notification, A1 and working-condition requirements.
Long-Term Posting to Spain: What Changes After 12 Months
When the actual duration of a posting exceeds 12 months, the company must guarantee posted workers virtually all working conditions provided under Spanish labour law, not only the core matters required for standard postings. The only matters excluded are the procedures for concluding and terminating the employment contract, including non-competition clauses, and supplementary pension schemes, which remain governed by the home country’s law.
Extending a Posting to 18 Months: The Reasoned Notification
If the company expects the actual duration to exceed 12 months, it can send the competent labour authority, before that period expires, a reasoned notification extending the standard posting regime up to a maximum of 18 months, delaying the point at which the full set of working conditions applies.
Replacing a Posted Worker: How the 12-Month Threshold Is Calculated
Article 3.8 of Law 45/1999 expressly addresses this scenario: if a company replaces a posted worker with another performing the same job at the same location, the posting duration for the 12-month threshold is the cumulative duration of each worker’s posting periods. “Same job at the same location” is assessed by looking at the nature of the service, the work performed, and the address of the workplace.
Even without a Spanish company, a prolonged or significant presence of posted workers can affect the company’s tax position. Spending more than 183 days in Spain does not automatically make a worker a Spanish tax resident: other criteria under domestic law and the applicable double taxation treaty also matter. Similarly, permanent establishment risk for the company does not depend only on the decision-making powers of posted staff, but can also arise from a fixed place of business, authority to conclude contracts, or duration thresholds specific to construction sites and installations. This deserves a separate assessment, particularly for prolonged or recurring postings.
Posting Workers to Construction Sites and REA Registration
When a posting involves a company that intends to be contracted or subcontracted for work on a construction or civil engineering project, an additional requirement applies: registration with the Registro de Empresas Acreditadas (REA), mandatory for postings exceeding eight days in this context.
This should not be confused with the posted worker notification or the A1 certificate: they are three distinct procedures, handled by different authorities. The first posting notification, in these cases, counts as the REA registration application only when it is accompanied by the declaration under the required template and the documentation set out in Royal Decree 1109/2007: it is not automatic from the notification alone. Requirements include evidence of occupational risk-prevention training for the staff involved. Once granted, REA registration is valid for three years across the whole of Spain, regardless of which Autonomous Community issued it.
Our dedicated guide to REA registration in Spain covers the procedure, requirements and timelines in full detail.
Temporary Work Agencies and Chain Postings to Spain
Posting through a temporary work agency carries additional requirements. The agency must accredit, together with the notification, that it meets the requirements set by its home State’s legislation to hire out workers to a user company, and state the user company’s temporary needs to be met through the supply contract. Unlike standard postings, the eight-day exemption never applies: notification is mandatory from the first day of activity.
A particular case is chain posting: a temporary work agency in one EU country posts a worker to a user company, which in turn sends the worker to Spain to fulfil a contract with a Spanish recipient, or assigns the worker to its own Spanish workplace or that of another company in its group. Spanish law generally treats the temporary work agency as the entity posting the worker to Spain, with the corresponding compliance responsibility. This can change depending on who actually exercises management authority over the worker: an aspect that needs to be assessed case by case.
Road Transport: Posting Rules for Drivers
Chapter V of Law 45/1999 sets out separate rules for road transport. Bilateral transport between the company’s home country and Spain, limited parallel services, and pure transit are generally not treated as posting; cabotage, non-bilateral transport, and additional operations beyond those limits generally are. Notifications for transport drivers are submitted through the IMI (Internal Market Information) system rather than the LEY45 portal.
UK and Non-EU Nationals Posted to Spain
UK companies can still post workers to Spain after Brexit, but must layer immigration requirements on top of the standard posting rules, since UK nationals are no longer covered by EU freedom of movement. Companies posting non-EU nationals face a similar dual track: work authorisation and, where required, a visa, in addition to the notification, representative and, where applicable, A1 or an equivalent certificate of coverage under the relevant bilateral agreement. Processing times for these authorisations can be significant and should be planned well before the posting date, and supporting documentation may need to be authenticated or apostilled to be valid in Spain.
Sanctions for Non-Compliance When Posting Workers to Spain
The Law on Infractions and Sanctions in the Social Order (LISOS), Articles 10 and 40, classifies breaches into three levels of severity. The applicable fine bands were increased by 20% under Law 10/2021, replacing the lower figures still quoted as current in several guides.
| Severity | Typical breach | Fine band |
|---|---|---|
| Minor | Formal errors or minor shortcomings in the notification | €70 to €750 |
| Serious | Late notification, failure to appoint a representative, or missing translated documentation when required | €751 to €7,500 |
| Very serious | Failure to notify the authorities, or false or concealed information | €7,501 to €225,018 |
The ITSS can request documentation during an inspection, at the workplace or digitally, including after the posting has ended. Companies that create the false impression that a posting falls within Law 45/1999 when it does not face more serious consequences: the worker becomes entitled to full Spanish labour and social security legislation, with additional liability for the company.
How Lawants Supports Companies Posting Workers to Spain
Companies that contact us about a posting rarely have a single isolated question. More often, they arrive with a notification to submit, a representative to appoint and working conditions to verify, without a clear view of whether these are separate procedures or one. Our approach is to anticipate issues, reduce risk and simplify the requirements, so the company can focus on the project rather than the paperwork around it.
For many companies, a posting is the first point of contact with Spain. The same companies, once they start hiring locally or manage the transfer of an executive, come back to us for the same reason: a single, stable point of contact providing consistent management of regulatory risk rather than assistance limited to a single filing.
We work with construction companies subject to REA, transport companies under sector-specific rules, and groups managing long-term intra-corporate postings and executive transfers across Europe. Each scenario has its own critical point, and we treat it as such.
Notification, representation and working conditions, coordinated before departure, not discovered one at a time.
We assist foreign companies posting workers to Spain and across Europe, from a single technical assignment to a long-term intra-corporate posting, with one stable point of contact coordinating notification, representation, social security and sector-specific compliance.
FAQ: Posting Workers to Spain
Answers to the questions we receive most often from companies posting workers to Spain.
What is a posted worker?
A posted worker is an employee temporarily sent by their employer to carry out work in Spain under a service contract, an intra-group assignment or a temporary work agency arrangement, while the employment relationship with the sending employer continues. Social security coverage is assessed separately and, where EU coordination rules apply, is normally evidenced by the A1 certificate. In Spain, this is governed by Law 45/1999.
Do posted workers need translated contracts?
Not by default. Employment contracts and other required documents do not need to be pre-translated and kept in Spanish for the whole posting. Translation into Spanish, or the co-official language of the relevant territory, is required when the documents are actually presented to the Spanish authorities.
What is the LEY45 portal?
The LEY45 portal is the Spanish Labour Inspectorate’s central online register for posted worker notifications. It lets companies submit the notification electronically in a single format, regardless of which Autonomous Community will host the activity.
Do I need to notify short postings under eight days?
It depends on the type of posting. For contract-based and intra-corporate postings under Article 2.1.1, the exemption applies when the duration does not exceed eight days, and it never applies to temporary work agencies. The law does not provide for an indiscriminate accumulation of every posting a company carries out over a period.
When must a company appoint a representative in Spain?
Where a posted worker notification is required, the company must identify a natural or legal person present in Spain who can act as liaison with the Spanish authorities and receive or send documents and notifications when necessary. Not necessarily tax resident or domiciled there, this person is designated within the notification itself.
What happens if I don’t apply for the A1 certificate?
Without an A1 certificate, Spanish authorities may determine that the posted worker should be registered under the Spanish social security system, potentially triggering back-payment obligations, late-payment surcharges and administrative penalties. The A1 certificate is the essential proof that the worker remains covered by their home country’s social security system.
What if I replace a worker during the posting?
When one posted worker is replaced by another performing the same job at the same location, the posting periods are added together for the purpose of the 12-month long-term posting threshold. A new notification is still required for the replacement worker.
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