Company lists · Data refreshed September 2026
Top 25 Outbound call centers based in the United Kingdom
RevenueBase identified 344 outbound call centers headquartered in the United Kingdom as of September 2026 and tracks 4,565 professional contacts across them, including 738 with verified work emails and 252 with mobile numbers. London is the largest hub.
This list covers outbound call centers headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest outbound call centers based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 243 | ||||
“The Telemarketing Company is one of the UK's most trusted telemarketing agencies, delivering flexible, high-quality voice services, including pre and post sales research…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 2 | 205 | ||||
“Established since 1998 Clearanswer is an expert provider of contact centre solutions.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 3 | 132 | ||||
“Dedicated and shared contact centre outsourcing operations.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 4 | 119 | ||||
“GCL, with its unique, non-scripted approach to telemarketing and related marketing services, has for over 30 years established an enviable reputation for providing winning lead…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 5 | 116 | ||||
“Since 2016, Air Marketing has been the trusted outsourced sales and lead generation agency in the UK for ambitious B2B businesses.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 6 | 114 | ||||
“EC Outsourcing is one of the UK's leading outsourced contact centres.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 7 | Youpro ContactIndirect evidence | 90 | |||
“A world class offshore outsourcing agency, with offices in London and Harare, we have access to some of the best educated, best spoken graduates you will find anywhere in the…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 8 | 83 | ||||
“We are Subfero.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 9 | 59 | ||||
“CallCare is your outsourced contact centre and customer service partner.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 10 | 57 | ||||
“At Contact Web, we deliver customer experience outsourcing differently.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 11 | 54 | ||||
“We are an established AI-enabled call centre specialising in every aspect of sales and customer service.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 12 | 47 | ||||
“4Marketing is a direct marketing agency devoted to generating new business opportunities for its clients through its focused new generation of telemarketing professionals.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 13 | 46 | ||||
“Direct Response can provide outsourcing of voice, data and contact centre services for organisation from a global business to a one-man operation, delivering outstanding service…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 14 | 45 | ||||
“Advance Connects are a B2B telemarketing, lead generation & appointment scheduling experts, operating within various sectors including construction, built environment, industrial…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 15 | 44 | ||||
“With over three decades of experience, we partner with B2B sales and marketing teams to drive and nurture new customer acquisition - securing conversations with the right…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 16 | 43 | ||||
“Beanstalk is an integrated B2B Telemarketing and Lead Generation agency dedicated to helping our customers win new business.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 17 | 43 | ||||
“B2B and B2C outsourced Telemarketing agency.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 18 | 41 | ||||
“From planning & recruiting to training & delivery, we provide unbeatable outsourcing services that are not only cost effective but surpass the average UK skill set.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 19 | 39 | ||||
“For over 20 years, Chase Response has delivered unrivalled standards in call centre outsourcing and customer management services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 20 | 38 | ||||
“Highly qualified B2B Sales Appointments you can trust.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 21 | 35 | ||||
“1 Stop Data offers the best of breed Marketing, Lead Generation and Call Centre services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 22 | 33 | ||||
“Working with clients across a variety of sectors, Paragon is a leading provider of B2B lead generation and appointment setting marketing projects with vast experience in creating…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 23 | TELUIndirect evidence | 32 | |||
“Telu is the complete business solution for generating leads and revenue for your business.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 24 | 31 | ||||
“IT Focus Telemarketing Ltd is an agency that specialises in working with information technology companies.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 25 | 28 | ||||
“Generating high-quality B2B sales leads for your business!” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
Showing 25 of 344 outbound call centers based in the United Kingdom
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Outbound call centers based in the United Kingdom at a glance
As of Sep 5, 2026Companies by employee count
Verified emails by last verification
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among outbound call centers, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in the United Kingdom whose own description of what they do matches “outbound call centers”. Matching reads each company's description, not its industry code or its name.
- What we exclude
- Companies whose own description does not clearly place them among outbound call centers, and records with no verified work email. Companies headquartered outside United Kingdom are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 738 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 5, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Outbound call centers by metro
- Outbound call centers in London62
Frequently asked
How many outbound call centers are there based in the United Kingdom?
RevenueBase identified 344 outbound call centers headquartered in the United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
The Telemarketing Company, headquartered in Brighton, tops this list with the largest team on record.
Which city has the most outbound call centers?
London leads with 62 headquartered companies, followed by Manchester (13) and Bristol (11).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 738 verified decision-maker contacts tracked across these 344 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 5, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
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