This frequently asked question explains the process you must follow if your organization has a valid authorization from the AEAT, but needs to expand it to add new data consumption or request authorization for new procedures for which you want to access data from the State Tax Administration Agency (AEAT).

In this case, it is not an initial registration, but rather an extension of data consumption for existing authorizations or a request for consumption for a new procedure.


AEAT authorization extension circuit

Therefore, this situation applies when:

  • Your entity is already authorized by the AEAT , and

  • Do you want to add new consumptions to an information supply that you already have authorized or request authorization for a new procedure?

In this case, it is not necessary to make a new initial registration or adhere to a new agreement, as long as the new procedures are covered by the current agreement with the AEAT.

Which form should I use?

To communicate new procedures you must use the same AEAT form that is used for initial registration .

Although the formal process to follow is the same, the objective of this procedure is to extend existing authorizations , not to register a new one.

You can download the form from the website corresponding to the purpose of the procedure (tax or non-tax), in the Forms, guides and models section, accessible from the following links:

AEAT website for tax purposes


AEAT website for non-tax purposes

You must complete all sections of the form following the instructions indicated.

The form itself includes, at the end, detailed instructions for filling in each field, which we recommend you follow to avoid errors or possible requests for corrections.

In this case, on the form you must indicate:

  • The new procedure that you need the AEAT to authorize.

  • Web services and access methods.

  • The reason for the presentation (communication of new purposes or procedures).


How and where is communication presented?

You will have to submit the form through the electronic registry of the AEAT headquarters , using the corresponding identification system:



You can access the registry indistinctly:

  • From the specific website according to the purpose of the procedure (tax or non-tax): a) Tax purposes


AEAT website for tax purposes

b) Non-tax purposes

AEAT website for non-tax purposes

  • Or, from the general catalog of procedures of the AEAT electronic headquarters, through the route: Inicio > Todas las gestiones > Otros servicios > Administraciones Públicas, where you can filter the procedures for tax and non-tax purposes:

a) Tax purposes


AEAT website for tax purposes

b) Non-tax purposes


AEAT website for non-tax purposes

In both cases, you will access the generic Electronic Registration form for document submission , in HTML format.



Example of generic form available in the electronic registry of the AEAT headquarters

This form:

  • The corresponding procedure and formalities are already automatically preset , depending on the purpose you select (ZA04 tax purposes or ZA05 non-tax purposes).

  • It allows you to attach the AEAT's own form to the procedure, completed and signed in PDF.

Therefore, you do not need to manually select the procedure or formality, as they are automatically included when you access the AEAT's electronic office from the enabled links.

The operation of the generic electronic registration form is explained on the help page of the AEAT's electronic office.

Once you have registered your request:

  • An acknowledgement of receipt is generated with a Secure Verification Code (CSV).

  • You can consult the file on the AEAT's electronic office.

Subsequently, the AEAT analyzes the request and, if applicable, authorizes access to the data you have requested.

What documentation must be submitted?

To process the notification of new procedures, you must present the following documentation:

  • The AEAT's own form, completed and signed, in PDF format.

The lack of this element may result in a request for amendment, which may delay processing.

Amendments and requirements from the AEAT

If the AEAT detects that the application submitted is incomplete or requires any correction, it will notify you of the amendment requirement.

In this case, you must submit the amendment through the authorized procedure of the AEAT electronic office, within the period indicated in the request:
Respond to requests or submit documentation related to a document received from the AEAT



AEAT website for access to the procedure

If you need help on how to submit an amendment or respond to a request, you can consult the following frequently asked questions on the AEAT's electronic office:
How to respond to requests or submit documentation related to a document received from the AEAT

What about the electronic seal certificate?

In communicating new procedures:

  • The electronic seal certificate is not modified if you continue to use the same one that you have already authorized.

  • You will have to inform it again on the form , indicating the serial number of the valid and authorized certificate.

Clarifying note : If the electronic seal certificate has not changed , you reported it and it was authorized during the initial registration or a subsequent renewal, you do not need to re-attach the public key in ZIP format.

Official authorization from the AEAT

Once the AEAT has analyzed the application, it will authorize , if applicable, the new procedure you have requested, updating the existing authorizations.
You will be notified by email , indicating the specific data you will be able to access.
From this moment on, you will be able to request the corresponding service through Via Oberta (AOC) , in accordance with the authorizations granted to you by the AEAT.

Final reminder

  • The communication of new procedures is not a new registration, but an expansion.

  • The form is the same as the initial registration form, but with a different reason for filing.

  • It is not necessary to re-attach the public key in ZIP format of the certificate during this procedure, since you already provided it during the initial registration or in a subsequent renewal.

Additional information