Solar without papers: it can be fixed, and it pays not to wait

How to know if your installation is legalised

There is a quick test: surplus compensation. If your bill shows no credit for the energy you export, the installation most likely never got registered with the grid distributor, and that means an incomplete file. The serious check walks the whole chain: responsible declaration at the town hall, electrical installation certificate, industry registration, entry in the self-consumption register and notification to the distributor.

What you are missing in the meantime

An unlegalised installation is not just a formal risk. It is money escaping every month:

• Surplus goes uncompensated: the energy you export is given away.
• The income-tax deductions, state and regional, require a legalised, registered installation. No papers, no deduction.
• Municipal IBI or ICIO rebates, where they exist, require proof of the installation. Another closed door.
• In a claim, your home insurer will ask about an electrical installation that officially does not exist.

How it gets regularised, step by step

The process mirrors a new installation's, adapted to works already done. First, a technical inspection on your roof: we verify that what was installed meets the regulations and can be certified as it stands, or what needs correcting first. Then the documentation is rebuilt, technical report included, the responsible declaration is filed with your town hall, the installation certificate is issued, and everything is registered with industry, the self-consumption register and your distributor to activate compensation.

The original company does not need to exist or answer your calls: the documentation can be rebuilt from the physical installation. And yes, we have regularised other people's installations more than once; it is as worthy a job as a new build, and among the most gratifying.

Why it should not be left to sleep

Every month without legalisation is surplus compensation that never comes back. And the tax deductions have a regulatory expiry date, with the current framework pointing at the end of 2026. If you suspect your installation sits in this limbo, the check is simple and comes out of one visit: bring your bill and the installation contract, and we will tell you exactly where in the chain your file stalled.

When the company that installed it no longer exists

It is the most common story we hear at our office in Xàtiva: the company came from out of town, fitted the system quickly, took the money, and a year later the phone number was dead. No installation certificate, no technical report, nobody to chase. The first reaction is usually anger, understandably, but the important thing to know is that the installation is not lost: the paperwork can be rebuilt even if the people who fitted it have vanished.

What an engineering firm does in these cases is survey the installation from scratch: a site visit, measurements, checks on the protections and cable sizing, identification of panels and inverter from their labels and serial numbers, and the drafting of the technical report that should have existed from day one. With that, and with a qualified installer signing the certificate, the file can start moving. Sometimes a surprise turns up, a missing protection or a cable on the thin side, and it gets corrected before anything is registered.

Before calling anyone, gather whatever you have, because every document saves work:

• The invoice and the contract, even if the company no longer exists
• Photos of the installation work, if you took any
• The make and serial number of the inverter, printed on its label
• Your CUPS supply code, which appears on any electricity bill
• Any email or paper the company ever sent you

The cases that complicate the file (and how they get solved)

Not every regularisation is the same. In the old town of Xàtiva, and generally in listed buildings or heritage (BIC) surroundings, the responsible declaration route provided by Decree Law 14/2020 and the TRLOTUP may not be enough: the town hall can require a licence and set conditions on how visible the panels are. That is not a reason to panic, it is a reason to check before moving the file, because the order of the steps changes.

Another frequent case in this comarca is the country house on scattered rural land: the installation exists and works, but the supply has its own history and sometimes the house's own paperwork is not tidy either. There the solar file crosses paths with the planning situation of the house itself, and it pays to look at the whole picture, not just the panels. And a third one: the silent extension. A small installation was legalised years ago, then someone added panels or swapped the inverter without touching the paperwork. For the file, what sits on the roof has to match what the documents say, so the extension drags its own regularisation along with it.

In all these cases the pattern is the same: first understand what is there, then choose the administrative route, and only then register. Doing it backwards, registering first and fixing later, is the recipe for a stuck file.

Frequently asked questions