Company lists · Data refreshed September 2026

Top 25 Outbound call centers worldwide

RevenueBase identified 3,009 outbound call centers worldwide as of September 2026 and tracks 85,914 professional contacts across them, including 6,549 with verified work emails and 7,027 with mobile numbers. The United States is the largest market and London the largest hub.

This list covers outbound call centers worldwide, 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 5, 2026. Country and city lists for outbound call centers follow the table.

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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 5, 2026 86% judged on-target in blind review
3,009Companies
85,914Contacts tracked
6,549Verified emails
7,027Mobile numbers
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The 25 largest outbound call centers worldwide

Ranked by team size
Top 25 of 3,009 outbound call centers worldwide, ranked by team size, largest first. Data refreshed Sep 5, 2026. RevenueBase Smart Search rates how each company's information relates to outbound call centers: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Strong evidenceBerwyn, PA, United StatesHQ checked Sep 5, 20265,001-10,0002,774 contacts →

Strong evidence

“Advanced Call Center Technologies, LLC (ACT) is a premier provider of domestic (USA), near shore and far shore outsourced call center services to the financial services, mortgage…”

Source: RevenueBase Database · checked Sep 5, 2026
2Partial evidenceAkron, OH, United StatesHQ checked Sep 5, 20261,001-5,0001,764 contacts →

Partial evidence

“InfoCision is an award-winning contact center partner trusted by leading brands for over 40 years.”

Source: RevenueBase Database · checked Sep 5, 2026
3Indirect evidenceBoca Raton, FL, United StatesHQ checked Sep 5, 20265,001-10,0001,741 contacts →

Indirect evidence

“Award-winning outsourcing partner with two decades of experience operating an exclusively nearshore strategy that delivers better performance, close to home, and at a lower cost.”

Source: RevenueBase Database · checked Sep 5, 2026
4Strong evidenceSt Petersburg, FL, RussiaHQ checked Sep 5, 20261,001-5,0001,198 contacts →

Strong evidence

“The Office Gurus (TOG) is a global call center and business process outsource provider of customer care, telemarketing, lead generation, appointment setting, order entry, accounts…”

Source: RevenueBase Database · checked Sep 5, 2026
5Partial evidenceHyderabad, IndiaHQ checked Sep 5, 20261,001-5,0001,076 contacts →

Partial evidence

“Even the markets know that we’re the good call’!”

Source: RevenueBase Database · checked Sep 5, 2026
6Indirect evidenceGoiânia, BrazilHQ checked Sep 5, 202610001+1,058 contacts →

Indirect evidence

“Em breve uma nova página da BTCC Conexão Cliente.”

Source: RevenueBase Database · checked Sep 5, 2026
7Partial evidenceRockville, MD, United StatesHQ checked Sep 5, 20261,001-5,000972 contacts →

Partial evidence

“Transparent BPO was founded to provide its clients with superior nearshore contact center services and business process outsourcing at competitive pricing.”

Source: RevenueBase Database · checked Sep 5, 2026
8Strong evidenceDoral, FL, United StatesHQ checked Sep 5, 20261,001-5,000902 contacts →

Strong evidence

“Our Company Inktel is a leading business process outsourcer that specializes in creating personalized call center solutions which enable our clients to increase market share…”

Source: RevenueBase Database · checked Sep 5, 2026
9Indirect evidenceHorsham, PA, United StatesHQ checked Sep 5, 2026501-1,000883 contacts →

Indirect evidence

“If you are interested in growing your business or increasing efficiency, AnswerNet has the expertise, technology, and people to help you take your company to new heights!”

Source: RevenueBase Database · checked Sep 5, 2026
10Indirect evidenceCedar Falls, IA, United StatesHQ checked Sep 5, 20261,001-5,000877 contacts →

Indirect evidence

“CBE Companies is the parent organization of CBE Customer Solutions and CBE Group.”

Source: RevenueBase Database · checked Sep 5, 2026
11Indirect evidenceDurban, South AfricaHQ checked Sep 5, 2026501-1,000718 contacts →

Indirect evidence

“Established in 2010, Talksure has developed a reputation for being a respected financial services provider and outsource business services partner.”

Source: RevenueBase Database · checked Sep 5, 2026
12Partial evidenceFortaleza, BrazilHQ checked Sep 5, 20261,001-5,000701 contacts →

Partial evidence

“A VECTOR SERVIÇOS é uma empresa especializada na criação, implantação e gestão de serviços de Contact Center.”

Source: RevenueBase Database · checked Sep 5, 2026
13Partial evidenceJaipur, IndiaHQ checked Sep 5, 2026501-1,000649 contacts →

Partial evidence

“We at Girnar Care work towards customer satisfaction and it is also a center of customer excellence.”

Source: RevenueBase Database · checked Sep 5, 2026
14Indirect evidenceSalisbury, NC, United StatesHQ checked Sep 5, 2026501-1,000542 contacts →

Indirect evidence

“We are customer service experts.”

Source: RevenueBase Database · checked Sep 5, 2026
15Strong evidenceAlabang, PhilippinesHQ checked Sep 5, 20261,001-5,000509 contacts →

Strong evidence

“ServiceFirst is a World Class Call Center and BPO with strategic locations around the globe providing an elevated Customer Experience to benefit your business with exceptional…”

Source: RevenueBase Database · checked Sep 5, 2026
16Strong evidenceCebu City, PhilippinesHQ checked Sep 5, 20261,001-5,000504 contacts →

Strong evidence

“AZPIRED is a world-class provider of call center outsourcing services, proudly operating multiple locations across the Philippines.”

Source: RevenueBase Database · checked Sep 5, 2026
17Indirect evidenceGurugram, IndiaHQ checked Sep 5, 20261,001-5,000488 contacts →

Indirect evidence

“Welcome to the India page of Transcom!”

Source: RevenueBase Database · checked Sep 5, 2026
18Indirect evidenceSão Paulo, BrazilHQ checked Sep 5, 2026201-500474 contacts →

Indirect evidence

“A HOME AGENT S.A.”

Source: RevenueBase Database · checked Sep 5, 2026
19Indirect evidenceNoida, IndiaHQ checked Sep 5, 20265,001-10,000467 contacts →

Indirect evidence

“DigiTech is one of the fastest growing Outsourcing & Offsourcing company in Delhi/NCR.”

Source: RevenueBase Database · checked Sep 5, 2026
20Strong evidenceBengaluru, IndiaHQ checked Sep 5, 20261,001-5,000455 contacts →

Strong evidence

“ExpertCallers, a Flatworld Solutions company, is a well-established and reputed modern day call center outsourcing company.”

Source: RevenueBase Database · checked Sep 5, 2026
21Indirect evidenceHouston, TX, United StatesHQ checked Sep 5, 20261,001-5,000454 contacts →

Indirect evidence

“SupportZebra is a business process outsourcing company based in the Philippines, with headquarters in the Houston,TX region, that specializes in: Sales & Marketing Retention |…”

Source: RevenueBase Database · checked Sep 5, 2026
22Partial evidenceWrocław, PolandHQ checked Sep 5, 20261,001-5,000434 contacts →

Partial evidence

“CCIG Group has been offering outsourced contact center services since 2002 and professionally supporting its business partners in the B2C and B2B sectors.”

Source: RevenueBase Database · checked Sep 5, 2026
23Partial evidenceSanta Ana, CA, United StatesHQ checked Sep 5, 2026501-1,000431 contacts →

Partial evidence

“About : Ansafone is the leading outsourced contact center solution provider for companies in the US and Canada and maintains international alliances for global reach.”

Source: RevenueBase Database · checked Sep 5, 2026
24Partial evidenceHurst, TX, United StatesHQ checked Sep 5, 202651-200428 contacts →

Partial evidence

“Alliance is a domestically operated, internationally recognized professional contact center specializing in lead generation and appointment setting.”

Source: RevenueBase Database · checked Sep 5, 2026
25Indirect evidenceMandaluyong City, PhilippinesHQ checked Sep 5, 2026501-1,000411 contacts →

Indirect evidence

“Magellan Solutions Outsourcing Inc.”

Source: RevenueBase Database · checked Sep 5, 2026

Showing 25 of 3,009 outbound call centers worldwide

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Outbound call centers worldwide at a glance

As of Sep 5, 2026
7.6%Verified-email coverage
8.2%Mobile-number coverage
28.6Average contacts per company
11-50Median size (employees)
2.1%Largest-city concentration · London
Sep 5, 2026Page data refreshed

Companies by employee count

1-10
834
11-50
1,000
51-200
674
201-500
266
501-1,000
126
1,001-5,000
80
5,001-10,000
14
10001+
7

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 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.
Coverage
18 countries, largest first: the United States, India, the United Kingdom, the Philippines, Germany, Italy, France, Canada, the Netherlands, Spain and 8 more. Country and city lists for outbound call centers are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “outbound 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 outbound 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 outbound call centers, and records with no verified work email.
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, 6,549 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 between September 5, 2026 and September 14, 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 location

19 lists · largest first

Every Outbound call centers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 outbound 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 outbound call centers are there worldwide?

RevenueBase identified 3,009 outbound call centers worldwide 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?

Advanced Call Center Technologies, LLC, headquartered in Berwyn, tops this list with the largest team on record.

Which country has the most outbound call centers?

The United States leads with 979 companies, followed by India (352) and the United Kingdom (344). Every outbound call centers list by country and city is linked on this page.

Which city has the most outbound call centers?

London leads with 64 headquartered companies, followed by Kolkata (35) and Los Angeles (29).

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 6,549 verified decision-maker contacts tracked across these 3,009 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled from the company graph between September 5, 2026 and September 14, 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.