Company lists · Data refreshed September 2026
Top 25 Sales development call centers based in London, United Kingdom
RevenueBase identified 196 sales development call centers headquartered in London, United Kingdom as of September 2026 and tracks 1,474 professional contacts across them, including 219 with verified work emails. Across the United Kingdom, London is the largest hub for this category.
This list covers sales development call centers headquartered in London, 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, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 29, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, 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 sales development call centers based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 205 contacts → | ||||
Strong evidence “EngageTech is the leading sales development partner for complex B2B technology companies operating in multi-stakeholder, enterprise sales environments.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 2 | 59 contacts → | ||||
Partial evidence “Looking to fill your calendar with qualified calls?” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 3 | 48 contacts → | ||||
Partial evidence “At Fly Pie, sales outsourcing isn’t a “done-for-you” service, it’s a growth engine we build with you.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 4 | 24 contacts → | ||||
Indirect evidence “Outbound Partners helps B2B companies generate pipeline through structured outbound.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 5 | 23 contacts → | ||||
Indirect evidence “ProspectAware are experts at Executive level appointment setting.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 6 | 18 contacts → | ||||
Indirect evidence “For Appointment Setting in The UK, We are dedicated and results driven professionals can use cold calling new potential customers as well as contacting past customers to help…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 7 | 16 contacts → | ||||
Indirect evidence “Big Wolf Marketing - Leaders in B2B Telemarketing, Lead Generation & Appointment Setting With a vast combined experience, implementing established and cutting edge innovative…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 8 | 14 contacts → | ||||
Partial evidence “We are an outsourcing agency specializing in sales, marketing, and customer support.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 9 | 13 contacts → | ||||
Partial evidence “Business Hunters is a strategic B2B enterprise sales consultancy that helps businesses accelerate revenue growth by managing the full sales cycle from prospecting to closing deals.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 10 | 10 contacts → | ||||
Partial evidence “Transaction Focus is a leading Global outsourced sales and marketing company with headquarters in the United Kingdom with connections and associates based in China,the USA…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 11 | 10 contacts → | ||||
Indirect evidence “Momentum Outbound helps growing SMEs run the operational side of commercial growth.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 12 | 8 contacts → | ||||
Indirect evidence “Experts in having great conversations, REAL Calling are part of the REAL Family that has been delivering industry-leading face to face fundraising for over 13 years in the UK.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 13 | 8 contacts → | ||||
Indirect evidence “At Summit Prospecting, we’re committed to guiding your business to the peak of success.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 14 | 8 contacts → | ||||
Indirect evidence “Founded in May 2007, O.B.S.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 15 | 7 contacts → | ||||
Indirect evidence “Perlon AI replaces manual outbound workflows with custom agents that drive new business pipeline.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 16 | 7 contacts → | ||||
Indirect evidence “Generating new business leads in a cost effective and scalable way is challenging in a B2B environment.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 17 | 6 contacts → | ||||
Indirect evidence “Gravitas helps technology companies build qualified pipeline through senior SDRs, not junior reps learning on your account.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 18 | 6 contacts → | ||||
Strong evidence “Britain's Number 1 Sales Development Resource Provider.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 19 | 6 contacts → | ||||
Partial evidence “At Reach Revenue we help businesses to grow, optimising sales and marketing functions.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 20 | 5 contacts → | ||||
Indirect evidence “The most effective way to grow your business is through high-quality conversations with decision-makers.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 21 | 5 contacts → | ||||
Partial evidence “Outbound Solutions is a business development consultancy with a proven track record in growing our clients’ businesses by delivering quality new business opportunities for our…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 22 | 4 contacts → | ||||
Strong evidence “Agents Network is a trusted Sales Development & Recruitment Agency, Our approach is to build successful client relationships through offering an effective range of Sales and…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 23 | 3 contacts → | ||||
Partial evidence “As experts in harnessing technology to enhance vital stages of the sales journey, we empower you to delegate tasks such as lead acquisition, nurturing, follow-ups, and data…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 24 | 2 contacts → | ||||
Indirect evidence “BringCommerce | Outbound Lead Gen That Actually Works We help B2B service businesses flood their pipeline with qualified leads by fixing positioning, power messaging and outbound…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 25 | 2 contacts → | ||||
Partial evidence “Get High-Quality Home Improvements Sales Appointments That Convert (Or We refund your money) A system that is designed to help home improvement businesses and generate an…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: sales development call centers. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names sales development call centers.
- Partial evidence
- Its own public description names part of sales development call centers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name sales development call centers. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 196 sales development call centers based in London, United Kingdom
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Sales development call centers based in London, United Kingdom at a glance
As of Sep 29, 2026Companies by employee count
Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 196 companies.
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 sales development call centers, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search 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 Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in London, United Kingdom whose own description of what they do matches “sales development call centers”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names sales development call centers), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among sales development call centers, and records with no verified work email. Companies headquartered outside London 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 its RevenueBase Smart Search 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, 219 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 29, 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.
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names sales development call centers, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many sales development call centers are there based in London, United Kingdom?
RevenueBase identified 196 sales development call centers headquartered in London, 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?
Engagetech, headquartered in London, tops this list with the largest team on record.
Which city in the United Kingdom has the most sales development call centers?
London leads the United Kingdom with 196 headquartered companies, followed by Manchester (32) and Birmingham (17).
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 219 verified decision-maker contacts tracked across these 196 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 29, 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 Smart Search, 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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