Before you write to any seller of a Spanish business, there is a fixed sequence of checks you can run yourself, today, for free, in about half an hour. This is the dry, canonical version of that sequence: each step, its source, what a result proves — and what it does not. One thing this pass will never do is tell you whether a listing is genuine; no checklist honestly can. What it produces is smaller and more useful: for every step, a question the seller should be able to answer, and a written file you walk in with.
Step 0 — the legal name and NIF (minutes 0–2, or the deal pauses here)
Ask, in writing: which legal entity or self-employed person operates this business, and what is its NIF? Without it, every register below is unusable — registers hold the legal name, and the sign over the door is not a legal name.
Proves: nothing by itself. Does not prove: an evasive answer proves nothing either — but a request for money made before the operator is named is a reason to pause and ask again, in writing.
Step 1 — reverse image search the photos (minutes 2–7)
Put the two or three most distinctive photos through Google Lens. You are looking for the same photos living another life: a listing in another city, a stock-photo site, a differently named business.
Proves: a hit is a question — why do these photos exist somewhere else? — that deserves an answer; photos are sometimes reused innocently (franchise template, old listing, broker stock shot). Does not prove: no hit means only that this search found nothing; original photos establish only that someone photographed a room.
Step 2 — the address, before anyone shows it to you (minutes 7–12)
Street View the address: does the storefront match the photos, and what is the capture date in the corner? It can be years old. Then the Catastro cadastral map: the parcel and its recorded use.
Proves: that a premises of this kind officially exists at this address. Does not prove: anything about the business, the lease, or who may sell — the Catastro locates the premises, no more. A «confidential» address is common and legitimate; it simply means the physical checks cannot run yet — and a deposit requested before the premises can even be identified is a payment request not yet documented.
Step 3 — BORME, the company acts (minutes 12–22)
Company acts — incorporations, administrator appointments, dissolutions — are published in the daily BORME bulletin. A practical free first pass is a web search of the exact legal name restricted to boe.es, then the variants: with and without «S.L.», with and without accents.
Proves: that certain acts were published — a company exists on paper, administrators were appointed. Does not prove: that the listing is genuine (real companies’ names get borrowed; your correspondent may have no connection to the entity), nor is it the current authoritative record — that is a paid extract from the Registro Mercantil. And the mirror rule: not finding the company does not mean a scam — sole traders appear in no company register, and a traspaso is often just a lease assignment with no company behind it.
Step 4 — the public insolvency register (minutes 22–26)
Search the name at the Registro Público Concursal, free.
Proves: a match is a fact to raise. Does not prove: absence there is absence from that register — not absence of financial trouble, and not a clear bill of anything.
Step 5 — the coherence read (minutes 26–30)
Now read the file as one story. Does the register’s history rhyme with the advert’s story — an administrator change a few years before a «retirement» sale, the same family surname stepping back and forward? Registers do not prove intentions; none do. What they offer is coherence: the story in the advert and the story in the public record, told twice by sources that never met. The best possible outcome of the half hour is boredom — everything lines up, and what you gained is the right to proceed calmly.
Search discipline throughout: write down the date and the exact queries. The honest formula, if a result matters later: no match for this name, in this source, on this date, searched this way. Nothing stronger.
Three rules that keep the pass honest
1. The registers hold the legal name, not the trade name — which is why step 0 is a gate, not a formality.
2. BORME publications are not the authoritative current record — the paid Registro Mercantil extract is; free searches lag and miss variants.
3. Absence from a register is not absence of trouble, and presence is not proof of a genuine deal — a search result is not a certificate, of anything, in either direction.
Source for all three: the published guide how to check a business-for-sale listing and the registers linked there.
Two local notes
Madrid: the city publishes an open dataset of premises and their recorded activity — the censo de locales — useful as an address-and-activity clue, not as proof of a licence.
Basque provinces and Navarre: they keep separate cadastral systems; the national Catastro map does not cover them, so the regional cadastre is the one to read.
The five questions to put in writing before any deposit
Which legal entity or self-employed person operates this business, and what is its NIF?
What is the exact address of the premises?
In what capacity are you selling — owner, shareholder, attorney, mandated broker?
Can we do a short video call from inside the premises, during opening hours?
Who — which named account, in whose name — would receive any payment, and on what written terms?
Every one of these costs a genuine seller nothing. What you learn is rarely in the answers — it is in which come back straight, and which come back sideways.
What the 30 minutes cannot do: tell you whether the lease will transfer, what the licence position is, or which debts in Spain follow a business activity to its next holder rather than staying with a company. That is the paid layer — ours or someone else’s — with documents in it. A file that looks orderly after this pass is not a cleared file. What the pass decides is something earlier: whether you arrive at the first meeting as a supplicant hoping to be liked, or as a person with a file.
A prompt worth stealing
Fill the brackets and paste into any AI assistant:
I found a listing for a Spanish business and I am about to run my own 30-minute registry pass: [paste the listing text]. Draft (1) the five written questions to the seller, adapted to this specific listing so I can send them as-is — the exact legal name and NIF of the operator, the exact address of the premises, the capacity in which they are selling, a short video call from inside the premises during opening hours, and who (which named account, in whose name) would receive any payment, on what written terms; (2) a search-log template for the pass — Google Lens on the photos, Street View plus Catastro on the address, BORME with the exact legal-name variants to query (with and without «S.L.», with and without accents), and the Registro Público Concursal — with a date line and an exact-query line for each source; and (3) the follow-up question to send if any answer comes back sideways. Do not tell me whether the listing is genuine or the business is sound — questions and document names only.
The assistant drafts questions; it does not check the business.
This pass is the free layer, run by you. The paid layer starts where it stops: the lease, the licence position, and which debts follow the activity rather than the company — read against documents, for your specific deal.
Check a listing →Sources and access: the public registers named above — Catastro (www1.sedecatastro.gob.es), BORME (boe.es/diario_borme), Registro Público Concursal (publicidadconcursal.es) and the Madrid open-data portal (datos.madrid.es) — were each opened and confirmed working on 19 August 2026. Google Lens (lens.google.com) responds but presents a consent screen before use. Related reading: which debts follow a Spanish business. General information about how to use public sources — not legal advice and not due diligence; what any result means for a specific transaction is a question for a lawyer in Spain. This article does not determine whether any listing, seller, broker, company or payment request is genuine, and is not a statement about any listing, seller or business. No client cases are described here.