An electrical boletin (BIE) is an electrical installation certificate for low voltage, aka Certificado de Instalación Eléctrica de baja tension, most commonly referred to simply as a boletin. 

The boletin stipulates the maximum permissible power capacity and ensures the quality and condition of the installation.

A boletin is an official document certifying the installation complies with the Spanish electrical regulations (REBT-2002).


Iberdrola has a record of all the electrical installations connected to their supply distribution network with a boletin.

The boletin is also registered with the industrial department at regional town hall.


A boletin is required by Iberdrola when applying for an electricity supply, or when applying to upgrade an electricity supply.

Iberdrola can insist on a boletin when an installation is over 20 years old. This is more often the case when a new electricity supply is arranged following a change of ownership to a property, or when arranging a new contract for a different tariff (e.g. changing from a standard rate tariff to a cheap night time rate tariff aka Day And Night Energy).


For properties built since 2002, a boletin can usually be issued without the need for any improvement work to the installation.

For properties built before 2002, some improvement work is required in order to bring the installation up to the current standard of the Spanish electrical regulations (REBT-2002). The extent of the work will depend on the age of the installation.

Once a boletin is obtained it can be presented to Iberdrola in order to apply for an electricity contract.

Boletins for resale purchases

It is not a legal requirement in Spain for the vendor of a resale property to provide a boletin at the point of sale.

However, it is recommended that the purchaser obtain a valid boletin, prior to the sale, in order to ensure that the installation complies with the current Spanish electrical regulations (REBT-2002).

Iberdrola may insist on a boletin before a new electricity contract can be issued in the purchasers name.

Boletins for commercial buildings

An electrical project (proyecto electrico) is required for commercial premises. The project is designed by an Electrical Engineer or Architect. An electrical contractor carries out the work according to the technical plans and specifications. The installation is periodically inspected during the work programme by the local authourised Industrial agency, OCA. On completion of the project the boletin can be issued.

Contact us if you require a boletin, We will happily guide you through the process.

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