What documents does an electrical installation need in Spain?

Document map

The project or MTD defines the installation. The CIE certifies the completed work. Technical direction records professional supervision where a project is mandatory, while an OCA provides independent regulatory inspection for ITC-BT-05 categories.

The owner's records

Keep the registration receipt, final drawings, manuals, maintenance information and inspection certificates. Where the works differ from the design, the final records should describe the installation that actually exists.

For the next part of the decision, see the guides to Electrical certificate and Project or MTD.

How to check whether your electrical file is complete

The electrical records should tell a consistent story from design to registration. Check the address, owner, use and power across the documents, then compare the single-line diagram with the actual board and circuits. A folder full of certificates may still be incomplete if it describes another unit or an earlier configuration.

For example, refurbishment might add air conditioning and a sub-board without updating the original project. The old CIE remains useful historical evidence, but may not cover the extension. A document review should establish what was retained, what changed and whether new calculations, certification or inspection are required.

For a property in Menorca, also retain the CAIB submission or registration receipt and later inspection reports. The CUPS identifies the electricity supply point; it is not a substitute for the technical file. Giving these references to your engineer or contractor saves repeated searches and helps establish the scope of the work.

What to keep in the property file after registration

Keep more than the electrical certificate. Retain the final project or MTD, drawings and circuit diagrams that reflect the installed work, the completion and inspection documents where required, and evidence of regional registration. Add the documents for later alterations to the same file; the original paperwork alone will no longer describe the installation as it stands.

If a document is missing, find out whether it was never produced or has merely been lost. The contractor, design engineer, former owner or registering authority may hold a copy. This distinction can save unnecessary repeat work and prevent an existing installation from being treated as new without examining its history.