Does the A1 count as an RNT or TC2?

It answers the same question, that the worker is insured and contributions are being paid, but it is not the same document. The reviewer has to accept it under that requirement, and sometimes it needs explaining.

How long does an A1 last?

Whatever the certificate itself states. As a general rule, the posting it covers cannot exceed twenty-four months.

Does a self-employed person coming to work in Spain need one?

Yes. A self-employed person who goes to carry out a similar activity in another country also uses the A1 to show they remain insured at home.

Our company is not in the European Union. What do we submit?

It depends on whether your country has a social security agreement with Spain. If it does, the posting certificate under that agreement. If not, check with a labour adviser whether the workers need to be registered here.

A1 certificate in Spanish CAE platforms: what to submit when asked for RNT, RLC or ITA

Why you have no RNT, RLC or ITA

The RNT, RLC and ITA are documents issued by the Spanish social security treasury. They only exist when a company has a contribution account in Spain and its workers are registered here.

A temporarily posted worker keeps paying contributions in their home country. That is why your company cannot download those documents: there is nothing to download. What the reviewer wants to know through them is whether the worker is insured and the employer is paying contributions, and for a posted worker that answer comes from a different document.

What the A1 certificate shows

The A1 is the certificate on the applicable social security legislation provided for in EU Regulations 883/2004 and 987/2009. It shows that, for the period it states, the worker remains subject to their home country's social security even while working in Spain.

Under Article 12 of Regulation 883/2004, a posted worker keeps their home legislation as long as the anticipated duration of the work does not exceed twenty-four months and they are not sent to replace another posted person. The same twenty-four-month rule applies to self-employed people who go to carry out a similar activity in another country.

Who issues it and when to apply

It is issued by the social security institution of the home country, at the request of the employer or of the self-employed worker. Apply before the posting starts: depending on the country, processing can take from a few days to several weeks.

Each certificate covers one worker and one specific period. If the job runs beyond the dates on the A1, a new one is needed for the remaining time; if the posting is expected to exceed twenty-four months, only an exceptional extension agreed between the institutions of both countries is possible.

If your company is outside the European Union

The A1 applies to postings between countries of the European Union, the European Economic Area and Switzerland. Since Brexit, the United Kingdom issues an equivalent certificate under the social security protocol of its agreement with the EU.

For other countries it depends on whether there is a bilateral social security agreement with Spain. If there is, the home institution issues a posting certificate under that agreement, which serves the same purpose. If there is not, the worker may have to be registered with Spanish social security, which is worth confirming with a labour adviser before committing to a start date.

How to submit it in the CAE platform

The usual approach is to upload the A1 under the requirement where the platform asks for the worker's RNT or ITA, or to ask the client to enable a posted-worker variant if their setup has one. Requirements in Nalanda, CTAIMA, e-coordina, Metacontratas, Obralia or Dokify are configured by each client, so the exact route changes from site to site.

If the requirement is mandatory and the reviewer rejects the A1 for not being the expected document, what works is writing to them to explain that the company does not pay contributions in Spain and that the A1 is the equivalent document. As a standardised European form, it is understood without translation in most cases. The most common rejections are about details, not about the document itself:

The A1 dates do not cover the whole period of work on site.
The name or ID number does not match the worker registered in the platform.
The A1 was issued for a different company from the one listed in the platform.
The certificate has expired because the job ran longer.
A new worker has joined and does not have their A1 yet.

What the A1 does not replace

The A1 only answers the social security question. It does not replace the posting notification to the labour authority, nor REA registration on construction sites, and it does not prove preventive training, medical fitness or liability insurance. Each of those requirements is reviewed separately in the platform.

How EntraObra can help

We review exactly what your client's platform is asking for, check that each A1 covers the right worker and dates, upload it under the requirement it belongs to and, if the reviewer rejects it, explain to them in writing why it is the equivalent document.

EntraObra is an independent document support service. We do not issue social security certificates and we are not a labour consultancy: the A1 is issued by your home institution, and questions about contributions are for your adviser. Final validation always rests with the client.

If you want to keep going, start with whatever is blocking you right now:

The posting of workers notification

REA registration explained

Foreign companies working in Spain