This requirement is set forth in Law 25/2013 of 27 December, which promotes the use of e-invoices and the creation of the accounting register for invoices in the public sector.

A specific computer program is required for issuing an e-invoice. The Ministry of Industry, Energy and Tourisms offers a free-of-charge program. Another option is to hire a third party e-invoicing service.

Once issued, e-invoices are sent through general e-invoice delivery points of the corresponding administration, and in the case of the General Administration of the State, this delivery point is called FACE.

Many public administration offices, including the General Administration of the State, have taken the liberty to waive this requirement for invoices amounting to €5,000.00. E-invoice issuance is therefore optional in these cases.

Finally, Administration providers who issue e-invoices are not obligated to use only this format. They may issue both e-invoices and paper invoices in the same fiscal year.