Website visitor identification: the UK guide

Information checked 25 September 2026.

Website visitor identification is software that tells you which organisations are visiting your website. It matches the IP address of each visit to a company, so a B2B team can see that, say, a manufacturer in Leeds read three product pages yesterday, even though nobody from that manufacturer filled in a form.

This guide explains how the technology works, how accurate it can be, what UK law expects of you and how to choose a tool.

What website visitor identification is

Website visitor identification turns anonymous website traffic into a list of named companies, with the pages each one viewed and when. It is used mainly by B2B marketing and sales teams to find out who is interested before those people get in touch.

Most visitors to a B2B website never fill in a form. Your analytics shows you how many people came and which pages they read, but not who they were. Visitor identification fills part of that gap by answering one question: which organisation did this visit come from?

A typical tool gives you:

• a feed of identified companies, with name, domain, industry, size and location;
• the pages each company viewed, how long it stayed and how it found you;
• alerts when a target account visits;
• a way to find contacts at the company, or push it into your CRM.

It is sometimes called reverse IP lookup, B2B website visitor tracking, visitor intelligence or company identification. The core idea is the same.

How IP-to-company identification works

When someone visits your site, their browser connects from an IP address. A small script on your pages reports the visit, and the tool looks up which organisation that IP address belongs to. If the address is registered to, or regularly used by, a known company, the visit is matched to that company.

In more detail, the process usually looks like this:

1. A script records the visit. You add a short JavaScript snippet to your site, much as you would for analytics. It reports each page view along with the page address and referrer.
2. The IP address is looked up. The tool checks the address against IP-to-company data. That data comes from sources such as network registration records, the organisation that operates the network (its ASN, or autonomous system number), reverse DNS host names and commercial business IP databases.
3. The network is classified. A good tool also works out what kind of network it is: a company's own network, a home broadband provider, a mobile network, a VPN, a cloud host or a bot.
4. The company is enriched. The matched company is given details such as website, industry, headcount and location, and linked to the pages viewed.
5. You act on it. You see the company in a feed, get an alert or send it to your CRM.

Lead Forensics describes the same basic approach: "a small piece of code, much like Google Analytics, which tracks the IP addresses of businesses visiting a website."⁸

Why it identifies companies, not people

An IP address usually points to a network, not a person. When someone browses from their office, the network belongs to their employer, so the company can be inferred. Who that person is cannot. UK-focused vendors are clear about this. Lead Forensics, for example, says: "The technology reveals the company, not the person."⁵

Some tools offer contact details alongside the company. Those contacts come from business contact databases. They are people who work at the company, not necessarily the person who visited.⁷

Some US tools offer person-level identification. RB2B, for example, offers it for US visitors only.¹²

Why Google Analytics can't do this

Google Analytics 4 can't show you company names. Google says that in GA4 "IP addresses are not logged or stored",¹ and GA4 has no report of visiting organisations. The free Clearbit Weekly Visitor Report, which some teams used for this, was withdrawn on 30 April 2025.¹⁴ Our guide to seeing which companies visit your website covers the options in detail.

How accurate is visitor identification?

Accuracy depends mostly on where your visitors browse from. Matches from corporate networks are usually reliable. Matches from home broadband, mobile networks, VPNs and cloud hosts are unreliable, because those IP addresses belong to a provider, not to the visitor's employer.

It helps to separate two ideas that vendors often blur:

• Match rate is the share of visits a tool can attach to some company.
• Accuracy is the share of those matches that are correct.

A tool can raise its match rate by counting weak matches as if they were strong ones. That produces a longer list, but more of it is wrong. When you read vendor claims, such as Lead Forensics' statement that it "identifies up to 80% of B2B visits",⁶ ask how the figure is measured and what counts as an identification.

What reduces accuracy

• Remote and hybrid working. People working from home browse from their broadband provider's network. The IP address points to the provider, not the employer.
• Mobile networks. Phones on 4G or 5G share IP addresses across very large numbers of users.
• VPNs and privacy tools. These send traffic through a third party's servers.
• Shared offices and managed networks. A co-working space or a building's shared connection can serve many businesses from one address.
• Cloud hosts and bots. Traffic from data centres is often automated, or passes through a proxy.
• Out-of-date data. Companies move and IP ranges are reassigned, so databases need constant maintenance.

What a good tool does about it

Look for a tool that separates strong matches from weak ones and tells you which is which. Scout gives every match a confidence score from 1 to 99 with a one-line reason, and flags ISP, residential, mobile, VPN and cloud traffic so it can't appear as a confirmed company. Other tools handle this differently. Ask each vendor how they deal with non-corporate traffic.

The simplest test is your own data. During a trial, check a sample of matches against companies you know have visited, such as customers who logged in or prospects you were emailing.

Is website visitor identification legal in the UK?

Yes, it can be used lawfully in the UK, but the responsibility sits with you as the website owner. You need a lawful basis under UK GDPR, a clear privacy notice and a decision on whether PECR requires consent for the script. Treat this section as an overview, not legal advice.

The main points:

• IP addresses can be personal data. The ICO says online identifiers such as IP addresses can make a person identifiable, alone or combined with other information.² Even when a tool reports only companies, the processing behind it may involve personal data.
• Legitimate interests is the usual lawful basis. It needs a three-part test (purpose, necessity and balancing), recorded in a legitimate interests assessment.³
• PECR covers the script, not just cookies. The ICO's guidance on storage and access technologies covers scripts, tags, web storage and similar technologies, not only cookies.⁴ Whether you need consent depends on what the script stores or reads and why.
• You are usually the controller. Vendors generally act on your behalf. Lead Forensics, for example, says the customer "is responsible for identifying and documenting the lawful basis for its use of Lead Forensics."⁷

Our guide to website visitor identification and GDPR covers each point in detail, with links to the ICO guidance.

What to do with the data

Visitor identification is most useful as an early signal, not as a finished lead list. Use it to decide who to research, who to prioritise and when to follow up. It does not replace a conversation.

Practical uses:

• Account-based marketing. Get alerts when target accounts visit, and see which pages they read.
• Sales follow-up. Give account owners context before a call, for example that the prospect has been reading the pricing page.
• Content and SEO. See which organisations your content attracts. With Search Console connected, see the searches associated with those visits.
• Pipeline reporting. Spot accounts already in your CRM that are researching again.

Two cautions. First, the person you contact may not be the person who visited, so write as if you are starting a conversation, not as if you watched them browse. Second, UK electronic marketing rules still apply to the email or call you make afterwards.

How to choose a website visitor identification tool

Choose on the things you can check: price and contract terms, how the tool handles weak matches, where your data is processed, and whether it fits your CRM and workflow. Then test it on your own traffic before you commit.

A buyer's checklist:

1. Pricing model. Is the price published? Is it based on traffic, identified companies or seats? What happens if your traffic grows?
2. Contract terms. Monthly or fixed term? Does it renew automatically? How much notice do you need to give? Are there built-in price rises?
3. Accuracy and transparency. Does the tool show how confident it is in each match? Does it flag ISP and mobile traffic, or count it?
4. Company or person. Do you need company-level identification, or contacts too? Where do contacts come from, and what does each one cost?
5. Data protection. Where is data stored? Are raw IP addresses kept? What does the vendor provide to help with your privacy notice and legitimate interests assessment?
6. Integrations. Does it connect to your CRM, Slack or Teams, and your analytics?
7. Trial. How long is it, does it need a card, and does it include enough volume to test properly?

UK tools at a glance

Published entry prices for common tools start from free up to a few hundred pounds a month, and some vendors quote only. Prices below are in each vendor's own currency and have not been converted.

For a detailed comparison, including contract terms, see our Lead Forensics alternatives page. If you are weighing up cost, read Lead Forensics pricing explained.

Try it on your own traffic

The quickest way to judge any tool is to run it on your own site for a couple of weeks. Scout's trial is 14 days with no card, and includes 50 identified visits and 10 Forager credits. Start your free trial or see the plans.

Lead Forensics, Leadfeeder, Leadinfo, Albacross, RB2B and HubSpot are trade marks of their respective owners. Scout is not affiliated with or endorsed by any of them. This guide is general information, not legal advice.

Frequently asked questions

What is website visitor identification? It is software that tells you which organisations are visiting your website. It looks up the IP address of each visit and matches it to a company, then shows you the company name, what pages they viewed and, in some tools, contacts at that company.

Can website visitor identification tell me who a person is? B2B tools used in the UK generally identify companies, not people. The company is inferred from the network the visit came from. Some US tools offer person-level identification for US visitors only.

How accurate is website visitor identification? It is most accurate for visits from corporate networks and least accurate for home broadband, mobile, VPN and cloud traffic, where the IP address belongs to a provider rather than the visitor's employer. Look for a tool that tells you how confident it is in each match.

Is website visitor identification legal in the UK? It can be used lawfully, but you are responsible for how you use it. That usually means a legitimate interests assessment under UK GDPR, a clear privacy notice and a decision on whether PECR requires consent for the tracking script. Take advice for your own situation.

Can Google Analytics identify companies visiting my website? No. Google Analytics 4 does not log or store IP addresses and has no report of visiting organisations. You need a dedicated tool to see company names.

How much does website visitor identification software cost? Published prices range from free plans with limits, through entry plans around €59 to €99 a month, to several hundred pounds a month for higher volumes. Some vendors, including Lead Forensics, quote on request. Scout starts at £349 a month.

Sources

Information checked 25 September 2026.

1. Google Analytics Help, IP masking support.google.com
2. ICO, What are identifiers and related factors? ico.org.uk
3. ICO, Legitimate interests ico.org.uk
4. ICO, Guidance on the use of storage and access technologies ico.org.uk
5. Lead Forensics, Website visitor identification leadforensics.com
6. Lead Forensics, Lead Forensics data leadforensics.com
7. Lead Forensics, Compliance customer FAQ leadforensics.com
8. Lead Forensics, Pricing leadforensics.com
9. Leadfeeder, Pricing leadfeeder.com
10. Leadinfo, Pricing leadinfo.com
11. Albacross, Pricing albacross.com
12. RB2B, Pricing rb2b.com
13. HubSpot Knowledge Base, Use buyer intent knowledge.hubspot.com
14. Clearbit, The future of Clearbit's free tools clearbit.com
15. Scout, Pricing scoutmetrics.co.uk