Company lists · Data verified August 2026

Top 25 Customer service outsourcing companies based in the United Kingdom

Name: Customer service outsourcing companies based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Verified Aug 28, 2026 456 companies tracked

There are 456 customer service outsourcing companies headquartered in the United Kingdom (RevenueBase, August 2026). RevenueBase tracks 32,318 professional contacts across them, including 5,694 with verified work emails and 1,130 with mobile numbers. London is the largest hub.

This list covers customer service outsourcing companies headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Data current as of August 28, 2026.

456Companies

32,318Contacts tracked

5,694Verified emails

1,130Mobile numbers

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The 25 largest customer service outsourcing companies based in the United Kingdom

Ranked by team size

Top 25 of 456 customer service outsourcing companies based in the United Kingdom, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#	Company	HQ	Employees	Contacts	Verified emails
1	RESQ	Seaham	1,001-5,000	493	149
2	Smartsourcing	Bristol	201-500	464	183
3	ANT Marketing	Sheffield	501-1,000	328	35
4	The Contact Company	Wirral	1,001-5,000	324	17
5	Ventrica	Southend-On-Sea	501-1,000	320	95
6	The Telemarketing Company	Brighton	201-500	242	39
7	Response	n/a	1,001-5,000	241	67
8	Clearanswer Call Centres	Leeds	501-1,000	202	24
9	Interact Contact Centres	Richmond	501-1,000	159	75
10	Ceuta Healthcare Part Of Ceuta Group	Bournemouth	51-200	150	60
11	Echo-U LTD	Newcastle Upon Tyne	201-500	140	7
12	Convergys Limited	London	51-200	137	4
13	We ARE Woven	Bristol	1,001-5,000	131	11
14	Exquisite Solution Limited	London	501-1,000	104	4
15	Rsvp Media Response LTD	London	201-500	95	22
16	Subfero	Bristol	51-200	84	2
17	FM Outsource	Bury	201-500	82	33
18	Loop Customer Management	Bradford	501-1,000	77	33
19	Connect Assist	Cardiff	201-500	73	24
20	Qormotho	London	51-200	63	6
21	Callcare	London	1,001-5,000	59	13
22	Impact Call Centre	Romsey	201-500	55	14
23	Orca Call Answering & Live Chat	Wrexham	51-200	54	12
24	Cymphony	Crewe	51-200	52	15
25	FLY PIE LTD	London	51-200	49	8

Showing 25 of 456 customer service outsourcing companies based in the United Kingdom

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Customer service outsourcing companies based in the United Kingdom at a glance

As of Aug 28, 2026

11-50Median size (employees)

LondonLargest hub · 144 HQs

1,130Contacts with mobile numbers

12Emails re-verified in last 30 days

Companies by employee count

1-10

156

11-50

146

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

Customer service outsourcing companies by metro

Metro	Companies
Customer service outsourcing companies in London	144
Customer service outsourcing companies in Manchester	20
Customer service outsourcing companies in Bristol	10
Customer service outsourcing companies in Birmingham	10
Customer service outsourcing companies in Leeds	9
Customer service outsourcing companies in Newcastle Upon Tyne	6
Customer service outsourcing companies in Leicester	5

How this list was built

Source: The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion: Companies whose own business descriptions match “customer service outsourcing companies”, with match quality audited by blind human judging, and headquartered in the United Kingdom.
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: Contact records re-verify on a rolling cadence; 12 contacts on this list were re-verified in the last 30 days.
Refresh: Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

How many customer service outsourcing companies are there based in the United Kingdom?

There are 456 customer service outsourcing companies headquartered in the United Kingdom as of August 2026 (RevenueBase).

What is the largest company on this list?

RESQ, headquartered in Seaham, tops this list with the largest team on record.

Which city has the most customer service outsourcing companies?

London leads with 144 headquartered companies, followed by Manchester (20) and Bristol (10).

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 5,694 verified decision-maker contacts tracked across these 456 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

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About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.