You already know who you want to sell to. What costs you is getting hold of them. List brokers sell you names (qualified or not, converting or not), and you pay before you find out which. Most of them don't sell you the names at all; they rent them to you for 12 months.
Winnowed is software that runs on your own computer. Tell it a trade and a place, and it counts every active company on the United Kingdom public company register that matches: free, in seconds, before you spend anything. If the number is worth having, it goes and finds the ones you can reach: website, email and phone, taken from each company's own site.
For sales and marketing teams who source their own prospects, and for anyone who has paid for a list and found 4 addresses in 10 were dead or belonged to somebody else.
To blow the chaff (the worthless husks) away from the grain, and more broadly to separate what is useful from what is not. What is left is smaller, and all of it is worth having.
No account, no card: the count is free. macOS and Windows.
The trade, not the job title. Marketing agencies, not marketing directors.
Examples: · ·
Tell it the trade you sell to, then press Count them. Your answer appears here.
You buy a list, or you build one. It arrives as a spreadsheet of names that all look plausible. Then you send, and that is when you find out. A tenth of ours bounced on the first day. Our sending platform paused the campaign on us before we had noticed anything was wrong. The domain takes the damage either way, and somewhere in that file is a company with no use for what you sell, reading an email about it.
A domain guessed from a company name will answer whether or not it belongs to that company. Nothing about a website that loads says it is the right one.
A bounce is how you learn a row was wrong, and by then the cost has already landed on your sending reputation rather than on the supplier who sold it to you.
You are handed whatever survived, with no way to judge how carefully it was chosen. A supplier that shows you only its successes is asking you to take its word for the rest.
Winnowed is built to fix the third one, because fixing the third one fixes the first two. A tool that has to tell you why it kept a company cannot keep one it never checked. Every row arrives with its reason: a website that was kept, with what proves it is theirs, and a refusal, with why.
And the cost stops landing on you. If a row names the wrong company you get the row back, and if the file is not what this page describes, you have 30 days to take your money back instead.
Before Winnowed there were 2 businesses of our own to fill a pipeline for, and 4 years of the platforms everybody uses to do it with. Filter, export, paste into a spreadsheet, and then spend longer working out which of the addresses were real than we had spent finding them.
And everyone on those platforms is working the same pool. The same companies, approached by the same people, in the same week. That is its own reason the replies do not come.
The hours were not the worst of it. The worst of it was sending to a list and not knowing which parts of it were wrong. One of our own domains sent 2,146 messages over 11 weeks with a broken sender record: 1 of the 2 checks that prove an email really came from you, failing every time. Mail went out. Nothing looked broken. Most of it arrived, because the other check was carrying it single-handed. We found out months later, which is the only way anybody ever finds out.
That is why the campaign guide comes with every plan, and why it carries the 2-minute check that almost nobody runs.
The lists we sent to kept everything and explained nothing. Winnowed does the reverse: it throws rows out, and it tells you why.
You open a small application and tell it which businesses you want and where. We answer from the company register, which we keep current, so there is nothing for you to download and nothing to go quietly out of date. Your machine then visits the website each business publishes itself and writes your list to your own Downloads folder. Your contacts never leave your computer.
In your own words. "Used car dealers", "letting agents", "people who fix boilers". It shows you which industry codes it matched, and you can correct it.
Finds the company's website and reads the contact page. A website only counts when it proves it belongs to the company: its registered number, its full registered name, or its registered address. If it cannot prove that, you get no website and no contact for that row, rather than a guess.
A spreadsheet file that opens in Excel, Numbers or Google Sheets, and imports straight into any sending tool. 15 columns, including company, its registered office address, website, what proves the website is theirs, email and phone, what each row is good for, and for every row, whether it was kept, refused or withheld, and why. Saved to your machine, not an account.
4 real companies from a real list. 2 kept, 1 refused, 1 held back, and every outcome carries the reason with it. Yours looks the same, whatever you sell.
Those 4 rows are ours. As a launch offer, 10 businesses get their own, in their trade and their area, with no card and nothing to cancel.
10 free lists of up to 500 companies, first come first served. Email your trade and area and you will hear back within 2 working days.
15 columns. What is in every row: company name · company number · town · registered office address, from the register · website · what proves the website is theirs, wherever a website is given · email address where one is published for the business · whether that address is a role address or the company's own name · telephone number where one is published · the trading address the website publishes, where it publishes one · what the row is good for (email, telephone, both, post to the registered office, or register data only) · and, where nothing was kept, the reason.
sales@, info@, enquiries@ and addresses in the company's own name come through, each one checked against the website that publishes it. 5 companies in 6 that publish anything publish one of these. Where the only address on a site belongs to a named person, the row still arrives (the company, its website, and its telephone number where one is published) with the person's address left where it is.
An address that identifies a person is personal data under the UK General Data Protection Regulation, and the obligations attached to it transfer to whoever holds it. A supplier who puts named individuals in your file has handed you a duty you did not ask for, priced into a spreadsheet, and you find out you own it when somebody objects. That is the line, it is the reason the file is built the way it is, and it is why a withheld row still gives you a way to reach the business.
What we will not tell you is that the rest carries no duty at all. Hold a file of business contacts and you are the data controller for it, with any list, from any supplier. You need a reason for holding it and you have to say where the details came from. 2 things make that lighter here than with a bought list, and both are how the file is built rather than promises: it is registered companies, so no sole traders, and no named individual's address is in it. The guide that comes with every plan sets out what you owe and the 2 lines that meet it.
Every row we have withheld on that rule still carried a website.
Anyone can find an address. The hard part is knowing whether it belongs to the company you asked for. Winnowed checks, and when it says no it tells you the reason in words you can verify yourself.
Those are real. coxinc.com is Cox Enterprises, an American media corporation. schaeffler.com is a German bearing manufacturer. Neither has any connection to the company that was asked for, and both were sitting in a live campaign list waiting to be emailed.
5 of those 7 lines were thrown away, which is roughly how a list gets built: most companies on the register never reach your file. How many do depends on the trade, and each one that does arrives with what proves its website is theirs. The rest arrive as a company, a website and a telephone number where there is one, with the reason there is nothing more.
Every refusal above is one we got right, and that is not the whole story. If Winnowed throws away a company you could have reached, you never see it. You just get a smaller file, and nothing tells you what is missing from it.
We publish a rate for rows given the wrong website: in a test of 500 companies across 10 trades in October 2026, 3 in 500 companies were given a wrong website, and 3 of the 83 websites delivered were wrong. The other direction has a number too, and it is the cost of the check: a right website was delivered for 16% of the 500, against 21% under the previous check. Most of the difference is a company's own site that prints no registered number, full name or postcode, so nothing on it proves it is theirs.
1 real run, 25 companies, nothing edited out. 5 came back with a usable address, and the other 20 carry the reason they did not: an individual's address withheld, a site with nothing published on it, a parked domain, no website found at all. Every row says which and why. Nothing to give us first.
See a real run, in full Download the sample file
One difference from the file you would buy: the part of each address before the @ is starred out here. The companies in this sample did not ask to be on a public web page, and publishing their addresses to make a point about not publishing people's addresses would be a poor way to make it. Your own file arrives complete.
120 companies, every address fetched and compared against the page it came from. A list built the ordinary way (guess the domain, take whatever answers) against one that verifies.
The second number is ours and it is not zero. The price is fewer contacts. In the same test a right website was delivered for about 1 in 6 companies (16%), against 21% under the previous check. Each website delivered shows what proves it is theirs. A row held back for want of proof says so, and names the possible website so you can look at it yourself.
Every supplier in this market publishes its best number. These are all of ours.
If a supplier will not tell you where their list is weak, they have not measured it, or they have, and would rather you found out afterwards.
Winnowed gets you the companies. How you approach them is yours: your own team, your own agency, your own tools, your own compliance process. Every business runs that differently and we are not going to tell you how to run yours.
What we can do is hand you the process we use ourselves, written down. 2 documents, with every plan, at no extra cost, with your first download. The first covers the 6 decisions below and why they go the way they do. The second is the same ground as button presses: which field, what to type in it, and the settings that are wrong by default. Take what is useful and ignore the rest.
Which platform, at what volume, and why your normal mailbox is the wrong place to do this.
A separate sending domain, 3 records, and a 4-week warm-up you can follow without thinking.
Who you may email without asking first, and what every message has to carry. Plainly, without the scaremongering.
3 emails, the intervals between them, and the point at which you stop and mean it.
1 company in 6 comes back with a number and no general address. Those are often the better calls.
3 numbers worth watching, 2 that will mislead you, and 1 silent failure to check for.
Every step in it exists because we got it wrong first and had to work out why. The walkthrough tells you which settings to change and the 2-minute checks worth running before you send anything, including the one that would have saved us 11 weeks.
Take the guide anyway. It is useful whether you buy anything or not, and it is the same document that comes with a paid plan.
One email with the guide in it. Unsubscribe in a click.
The application is free to download and does nothing without a subscription key. The key is what unlocks the register. The register lives at our end, built from the file Companies House publishes, so there is nothing for you to download or maintain. What you pay for is how many companies you want contact details for. We rebuild the register from the latest Companies House file at least every 3 months. The copy in use today is from .
The application, and a count of any trade, anywhere, as often as you like.
Launch offer: a free list of up to 500 companies, by request, until 31 October.
Count your marketStart with one market.
Buy StarterEnough to work a national market, or several trades side by side.
Buy Team6-month minimum. Each month's allowance does not carry over.
Buy PipelineTell us the trade and the area. We build the list and send you the file. Within 2 working days for a single run.
Ask for a quote2,000 means 2,000 companies checked. Each one is in your trade and your area, its website looked for and, where there is one, read, and it lands as a row in your file: a way to reach them, or the reason there is not one. You never pay for the same company twice, and counting your market costs nothing.
Start with one market. Upgrade and pay only the difference. Moving from Starter to Team costs £376, the difference in list price, and your renewal date stays the same. Moving between a yearly plan and Pipeline is arranged with us by email.
Building lists for clients? That needs an agency licence. Tell us how many clients and we will price it, or let us run the markets for you.
Build a list, open the file, look at what came back. If it does not do what this page says it does, write to us inside 30 days and we refund you in full: your money, not a credit and not an account balance. You do not have to win an argument first: the reason every row was accepted or refused travels in the file, so you can check the claim against your own list before you decide.
And separately, for as long as you subscribe: if a row names the wrong company, you get the row back. In a test of 500 companies across 10 trades in October 2026, 3 were given a wrong website, and 3 of the 83 websites delivered were wrong. That is our number and it is not zero. Find a row whose website does not belong to the company beside it, tell us which one within 30 days of the run, and we credit that company back to your allowance. Each row can be credited once, as allowance, never as cash.
The price shown is the total payable.
A file lands in your Downloads folder. 2,000 companies went in, and 2,000 rows came out. Each website in it carries what proves it is the company's, and every row without one says why.
You write one email. It goes to a list that does not bounce, your sending domain stays intact, and the following week is spent talking to the people who replied rather than arguing with a spreadsheet.
That is the whole of it. Not more contacts than anyone else will sell you, but fewer that turn out to be nothing.
Tell it the trade you sell to and a postcode. It will show you how many companies are there, which industry codes it matched, and how many are likely to come back with a usable address. No account, no card.
No account, no card. The count takes a second and costs nothing.