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Protocol for the implementation of the provision of tax information to Local Entities adhered to the Agreement for the Exchange of Tax Information and Collaboration in Collections Management (PROTEELL - June 2021)

3.3.1.Description of this information provision channel

Web services technology involves IT developments by the entity requesting information, for the implementation of the information retrieval system in its applications.

Once developed by the IT services, the authorised body shall enter in its certificate request application the identification data of the data subject from whom it wishes to obtain information, the purpose of the request and the type of certificate requested.Before sending the request to the web service of the issuing body, you must sign the request message.The signature of the request message shall follow the XML-DSig protocol.

A secure channel (SSL tunnel) will be established to send the request.The Tax Agency's web services require customer authentication when establishing this channel.In order to successfully establish this tunnel, the electronic certificate used for this purpose must have been authorised by the AEAT.

Therefore, for the submission of an application, one or more electronic certificates will be used at two points in time:for the signing of the petition and for the establishment of the secure channel.It is not necessary for these actions to be carried out with the same certificate, but it is necessary for this situation to be communicated to the AEAT, which will associate them with the requesting body.

Once the request message has been generated and sent by the requesting body, the issuing body shall verify that the requesting body is authorised to invoke the requested web service.After this check, the issuing body will process the request, issuing an electronically signed response (xml formatted document containing all related data) which will be sent to the requesting body in a synchronous manner.

For further information, please contact

CAT - AEAT Call Centre

  • Telephone:901 200 349


The technical specifications for making requests for bank deposit and investment fund information via web services can be found at Index of web services for information provisionNew window.These requests are answered immediately.