Company lists · Data refreshed September 2026
Top 25 Customer retention outsourcing firms worldwide
RevenueBase identified 1,308 customer retention outsourcing firms worldwide as of September 2026 and tracks 54,175 professional contacts across them, including 4,266 with verified work emails. The United States is the largest market and Lahore the largest hub.
This list covers customer retention outsourcing firms 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 28, 2026. Country and city lists for customer retention outsourcing firms 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.
The 25 largest customer retention outsourcing firms worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 4,126 contacts → | ||||
Indirect evidence “Mais que call center: soluções que transformam o seu negócio e a jornada dos clientes!” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 2 | 2,774 contacts → | ||||
Indirect 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 28, 2026Thanks. The Data Team will review it. | |||||
| 3 | 2,342 contacts → | ||||
Indirect evidence “Más que un contact center y BPO, somos el partner que asegura que la experiencia de tus clientes sea increíble.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 4 | 1,710 contacts → | ||||
Partial evidence “Support Services Group (SSG) helps businesses accelerate growth and earn customers for life through high-touch, outsourced engagement center services.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 5 | 1,404 contacts → | ||||
Partial evidence “NCO's Customer Fit Solutions are Custom Fit.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 6 | 1,198 contacts → | ||||
Partial 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 28, 2026Thanks. The Data Team will review it. | |||||
| 7 | 1,023 contacts → | ||||
Indirect evidence “En iké todos los días brindamos soluciones de personas hacia personas alrededor del mundo, aumentando la oferta de empresas que preocupadas por brindar respaldo, seguridad y…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 8 | 917 contacts → | ||||
Indirect evidence “Our People.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 9 | 911 contacts → | ||||
Indirect evidence “Somos a união da Liderança, e seus 34 anos de atendimento humanizado, com a Emdia, e sua expertise em inovação.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 10 | 902 contacts → | ||||
Indirect 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 28, 2026Thanks. The Data Team will review it. | |||||
| 11 | 873 contacts → | ||||
Indirect evidence “At Convergys Intelligent Contact, we build sustainable revenue streams for our clients.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 12 | 682 contacts → | ||||
Partial evidence “WEngage creates the best and authentic customer experiences driven by skilled employees, cutting-edge technology and certified working procedures.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 13 | 569 contacts → | ||||
Strong evidence “Vertex is a leader in BPO and Customer Management Outsourcing, serving over 200 clients worldwide across many sectors.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 14 | 542 contacts → | ||||
Partial evidence “We are customer service experts.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 15 | 517 contacts → | ||||
Indirect evidence “iContact BPO is in the business of transforming global enterprises - because we provide the BPO solutions that organizations need to provide exceptional service.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 16 | 515 contacts → | ||||
Indirect evidence “ContactUs Communications is a U.S.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 17 | 509 contacts → | ||||
Partial 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 28, 2026Thanks. The Data Team will review it. | |||||
| 18 | 474 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 19 | 455 contacts → | ||||
Partial evidence “ExpertCallers, a Flatworld Solutions company, is a well-established and reputed modern day call center outsourcing company.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 20 | 447 contacts → | ||||
Partial evidence “Proper Business solutions is offering a comprehensive suite of customer care call center services, outbound and lead generation, back-office and data processing solutions to…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 21 | 434 contacts → | ||||
Partial evidence “We are a people-focused business that provides outsourced contact centre solutions and specializes in customer life cycle management.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 22 | 430 contacts → | ||||
Partial evidence “Millennium1 Solutions is now NTT Business Process Outsourcing.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 23 | 354 contacts → | ||||
Indirect evidence “For over 35 years, The Connection has made a name for ourselves becoming one of the top industry partners to Fortune 500 companies looking to outsource their contact center…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 24 | 346 contacts → | ||||
Partial evidence “As a distinguished global leader in call center outsourcing, OnBrand24 takes pride in its 30-year legacy of delivering exceptional inbound and outbound call center services across…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 25 | 318 contacts → | ||||
Partial evidence “We are a diversified services company with extensive experience in design and execution of customer engagement programs meeting diverse requirements of our clients.” Source: RevenueBase Database · checked Sep 28, 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: customer retention outsourcing firms. 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 customer retention outsourcing firms.
- Partial evidence
- Its own public description names part of customer retention outsourcing firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name customer retention outsourcing firms. 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 1,308 customer retention outsourcing firms worldwide
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Customer retention outsourcing firms worldwide at a glance
As of Sep 28, 2026Companies by employee count
Email recency is reported on each country list linked below.
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 customer retention outsourcing firms, 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
- Every country. Country and city lists for customer retention outsourcing firms are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “customer retention outsourcing firms”. 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 customer retention outsourcing firms), 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 customer retention outsourcing firms, 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, 4,266 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 28, 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.
Customer retention outsourcing firms by location
6 lists · largest firstEvery Customer retention outsourcing firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Customer retention outsourcing firms based in the United States224
- Customer retention outsourcing firms based in India103
- Customer retention outsourcing firms based in the United Kingdom48
- Customer retention outsourcing firms based in Brazil44
- Customer retention outsourcing firms based in Canada30
- Customer retention outsourcing firms based in Germany25
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 customer retention outsourcing firms, 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 customer retention outsourcing firms are there worldwide?
RevenueBase identified 1,308 customer retention outsourcing firms 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?
Callink, headquartered in Uberlandia, tops this list with the largest team on record.
Which country has the most customer retention outsourcing firms?
The United States leads with 224 companies, followed by India (103) and the United Kingdom (48). Every customer retention outsourcing firms list by country and city is linked on this page.
Which city has the most customer retention outsourcing firms?
Lahore leads with 30 headquartered companies, followed by Manila (13) and Rawalpindi (12).
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 4,266 verified decision-maker contacts tracked across these 1,308 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 28, 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.