How do you know when a competitor has closed down?

When a competitor closes, their customers do not stop needing the work. They go looking, usually that week, usually by searching the thing the closed business used to rank for.

That is the cheapest demand available to a small business, and most never notice it happened.

Why acting on a rumour is worse than missing it

The failure mode is specific and expensive: you decide a rival has closed, you adjust your marketing accordingly, and they are trading. Now you are the business telling their customers they have gone — which is defamatory if you say it out loud, and merely embarrassing if you only implied it.

From outside, a trading business with a neglected website looks exactly like a closed one. No posts for six months, an unanswered phone, a listing marked permanently closed by a stranger. Each of those has an innocent explanation and all three are common.

So the evidence is tiered

Official tier — the company register. A company status of dissolved, liquidation or administration is a matter of public record with a legal process behind it. UK Companies House publishes it through a free API. This is the only tier that can support a published closure on its own, because it is the only one where somebody with legal duties filed something.

Operator tier — the business's own site. A closure notice on their own page is strong, but it is not official: pages go stale, and a notice can be months old or about one branch.

Everything else — listings, directories, observations. Weak individually, and useful only in combination.

What the two-source rule is actually for

Below the official tier, two independent sources are required before anything publishes.

The word doing the work is independent. A directory that copied a notice from the company's own page is one source twice. Aggregators copy from each other constantly, so three listings agreeing can easily be one observation with three URLs — and counting them as three is precisely how a rumour becomes a fact in a dashboard.

And without a register key there is no official source at all. That is not a degraded mode to be worked around; it is when the two-source rule is doing the whole job, which is what it exists for.

What to do when it is real

Not a word about them. Their former customers are searching for a service, not for news, and a business that announces a rival's closure reads as a business that enjoyed it.

What works is dull: be findable for what they were found for. The searches that used to reach them are now unanswered — their trade plus their town, their brand name plus a complaint, the specific service they were known for. Pages that say specifically where you work are what catch those.

If they had reviews mentioning something they were good at, that is a clue about what their customers valued, and it is a legitimate use of competitive research that stays out of knocking copy.

What it cannot tell you

Why. A closure may be retirement, a sale, a move, or a failure, and the marketing response differs: a retiring tradesperson may be recommending somebody, and it could be you.

The question to ask before you act on it

Which source says this, and what is behind that source?

If the answer is a listing somebody updated, wait. If it is a filing, it happened.