Authority for a third party to file your tax return online with the AEAT

The “Modelo de representación para la presentación por medios electrónicos de autoliquidaciones, declaraciones y comunicaciones tributarias” is an official form of the Spanish Tax Agency (Agencia Tributaria, AEAT) for voluntary representation under Article 46 of the General Tax Law (Ley 58/2003). With it a taxpayer allows an AEAT collaborator — a gestor, tax adviser or their firm that has joined a collaboration agreement (colaboración social) — to file online on their behalf a return for the stated tax and year.

The authority is narrow: this electronic filing only. Under this form the collaborator does not become your representative in other acts and does not receive AEAT notices for you. The text is standardised and may not be changed; FoxDocs only enters data into the fields of the official PDF.

• the grantor is the taxpayer, an individual or an entity (through its legal representative, whose authority is proved by an attached document);
• spouses filing a joint return both grant the authority;
• the representative is a collaborator who has joined an AEAT agreement; they sign the form and answer for the authenticity of the grantor’s signature and ID copy;
• the form is not submitted to the AEAT: the representative keeps it, and the AEAT may ask to see it.

• grantor: name and surnames, NIF and tax address (municipality, street, house number);
• spouse for a joint return — the same details;
• if an entity grants it — its name, NIF and tax address, plus its legal representative’s details;
• representative: name, NIF and the organisation that has the collaboration agreement with the AEAT;
• the tax (IRPF, IVA, IS…) and the tax year of the return;
• place and date of signature of the grantor and the representative.

• a copy of the DNI or foreigner’s ID of each grantor — it is attached to the form;
• for an entity — the document proving the signatory’s authority and the entity’s stamp (note 4 of the form).

1. Tell the chat in any language who grants the authority, who the representative is and which return they file.
2. The assistant asks for NIFs and tax addresses and adds the signing date.
3. Download the PDF, check it, sign it with the representative and hand it to them with a copy of your DNI or NIE.

Official form, Agencia Tributaria: sede.agenciatributaria.gob.es — Modelos de autorización de trámites para colaboradores sociales. Checked 2026-10-09. This is not legal advice.