Company lists · Data refreshed September 2026

Top 25 Quality assurance companies for contact centers worldwide

RevenueBase identified 761 quality assurance companies for contact centers worldwide as of September 2026 and tracks 23,958 professional contacts across them, including 2,434 with verified work emails. The United States is the largest market and Sao Paulo the largest hub.

This list covers quality assurance companies for contact 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 29, 2026. Country and city lists for quality assurance companies for contact 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 29, 2026 86% judged on-target in blind review
761Companies
23,958Contacts tracked
2,434Verified emails
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The 25 largest quality assurance companies for contact centers worldwide

Ranked by team size
Top 25 of 761 quality assurance companies for contact centers worldwide, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to quality assurance companies for contact 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 evidenceGuayaquil, EcuadorHQ checked Sep 29, 20261,001-5,0001,225 contacts →

Strong evidence

“We deliver tailored Contact Center and Back Office solutions to our strategic partners, leveraging advanced technology and high quality standards to elevate customer experiences…”

Source: RevenueBase Database · checked Sep 29, 2026
2Indirect evidenceHyderabad, IndiaHQ checked Sep 29, 20261,001-5,0001,076 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 29, 2026
3Indirect evidenceMadrid, SpainHQ checked Sep 29, 2026501-1,000686 contacts →

Indirect evidence

“Consultora especializada en servicios de Aseguramiento de la Calidad del Software dirigidos a controlar y mejorar los costes, plazos y calidad del ciclo de vida de los productos…”

Source: RevenueBase Database · checked Sep 29, 2026
4Strong evidenceAtlanta, GA, United StatesHQ checked Sep 29, 20261,001-5,000478 contacts →

Strong evidence

“Alvaria CX, the global leader in contact center solutions, emerged from the 2021 merger of Noble Systems and Aspect, bringing over 50 years of CX innovation.”

Source: RevenueBase Database · checked Sep 29, 2026
5Partial evidenceCape Town, South AfricaHQ checked Sep 29, 20261,001-5,000451 contacts →

Partial evidence

“Capita is an award-winning contact centre service company with fully hosted global delivery centres trusted by global leading brands to transform their Customer Experience.”

Source: RevenueBase Database · checked Sep 29, 2026
6Indirect evidenceToronto, ON, CanadaHQ checked Sep 29, 20261,001-5,000430 contacts →

Indirect evidence

“Millennium1 Solutions is now NTT Business Process Outsourcing.”

Source: RevenueBase Database · checked Sep 29, 2026
7Indirect evidenceFalls Church, VA, United StatesHQ checked Sep 29, 202651-200415 contacts →

Indirect evidence

“For 15 years, Astegic has been helping Fortune 500 through startup companies with their Testing & QA needs.”

Source: RevenueBase Database · checked Sep 29, 2026
8Strong evidenceChileHQ checked Sep 29, 2026201-500390 contacts →

Strong evidence

“Soluciones integrales de Contact Center.”

Source: RevenueBase Database · checked Sep 29, 2026
9Strong evidenceHalifax, NS, CanadaHQ checked Sep 29, 2026501-1,000367 contacts →

Strong evidence

“Here’s our ten-second elevator pitch: we provide affordable, onshore and/or nearshore, high-touch customized contact center solutions for brands who care deeply about the quality…”

Source: RevenueBase Database · checked Sep 29, 2026
10Strong evidenceBenito Juárez, MexicoHQ checked Sep 29, 20261,001-5,000338 contacts →

Strong evidence

“29 años de experiencia brindando soluciones integrales de contact center que superen las expectativas de nuestros clientes, a través de un equipo altamente capacitado, tecnología…”

Source: RevenueBase Database · checked Sep 29, 2026
11Strong evidenceSao Paulo, BrazilHQ checked Sep 29, 2026201-500337 contacts →

Strong evidence

“Somos uma empresa de contact center que tem como foco a satisfação dos clientes.”

Source: RevenueBase Database · checked Sep 29, 2026
12Strong evidenceBuenos Aires, ArgentinaHQ checked Sep 29, 2026501-1,000330 contacts →

Strong evidence

“Diseñamos estrategias a medida y nos destacamos por ofrecer calidad, flexibilidad y eficiencia en nuestros servicios de Contact Center.”

Source: RevenueBase Database · checked Sep 29, 2026
13Strong evidenceSioux Falls, SD, United StatesHQ checked Sep 29, 20261,001-5,000329 contacts →

Strong evidence

“Five Star Call Centers is a onshore and nearshore contact center outsourcer where we deliver outrageously amazing customer experiences for our clients and their customers.”

Source: RevenueBase Database · checked Sep 29, 2026
14Strong evidenceToronto, ON, CanadaHQ checked Sep 29, 2026501-1,000306 contacts →

Strong evidence

“Optima Communications International (OCI) is a Canadian contact center and business process outsourcer (BPO) specializing in regulated and complex industries, including utilities…”

Source: RevenueBase Database · checked Sep 29, 2026
15Indirect evidenceSanto Domingo, Dominican RepublicHQ checked Sep 29, 2026501-1,000281 contacts →

Indirect evidence

“With today’s informed and interconnected consumers, businesses must go the extra mile to ensure the utmost level of customer service from their employees.”

Source: RevenueBase Database · checked Sep 29, 2026
16Strong evidenceCaracas, VenezuelaHQ checked Sep 29, 20261,001-5,000265 contacts →

Strong evidence

“Somos una empresa con experiencia en el área Centros de Contacto (Contact Center), con experiencia en la gestión general de productos de consumo masivos, corporativos y…”

Source: RevenueBase Database · checked Sep 29, 2026
17Indirect evidencePrinceton, NJ, United StatesHQ checked Sep 29, 2026501-1,000264 contacts →

Indirect evidence

“ExpertCallers (a division of Flatworld Solutions) is a global consulting and outsourcing company, with a wealth of experience in providing operational and strategic excellence to…”

Source: RevenueBase Database · checked Sep 29, 2026
18Partial evidenceSanta Clara, CA, United StatesHQ checked Sep 29, 2026201-500249 contacts →

Partial evidence

“Quality in An AI Driven World.”

Source: RevenueBase Database · checked Sep 29, 2026
19Strong evidenceIowa City, IA, United StatesHQ checked Sep 29, 2026501-1,000235 contacts →

Strong evidence

“CONTACT CENTER SERVICES INNOVATIVE, HIGH-PERFORMANCE SOLUTIONS THAT WORK Mass Markets executes domestic omni-channel, inbound and outbound contact center services on behalf of…”

Source: RevenueBase Database · checked Sep 29, 2026
20Indirect evidenceNavi Mumbai, IndiaHQ checked Sep 29, 2026501-1,000214 contacts →

Indirect evidence

“Hansa Direct – a part of Hansa Customer Equity, is a one-of-a-kind Customer Experience Centre backed by specialists across data, analytics, MarTech and digital.”

Source: RevenueBase Database · checked Sep 29, 2026
21Partial evidenceMchenry, IL, United StatesHQ checked Sep 29, 2026501-1,000211 contacts →

Partial evidence

“Pro QC International provides tailored quality solutions with a human touch in 100 countries.”

Source: RevenueBase Database · checked Sep 29, 2026
22Indirect evidenceBengaluru, IndiaHQ checked Sep 29, 202651-200206 contacts →

Indirect evidence

“Convin is an Omnichannel AI Agent Platform for customer conversations that turns B2C interactions into revenue.”

Source: RevenueBase Database · checked Sep 29, 2026
23Indirect evidenceWinter Park, FL, United StatesHQ checked Sep 29, 202651-200182 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 29, 2026
24Strong evidenceItalyHQ checked Sep 29, 202651-200174 contacts →

Strong evidence

“One os si presenta sul mercato dei Contact Center focalizzandosi nei settori Insurance, Energy e Utilities.”

Source: RevenueBase Database · checked Sep 29, 2026
25Strong evidenceNew York, NY, United StatesHQ checked Sep 29, 20261,001-5,000171 contacts →

Strong evidence

“Zero Variance by Ubiquity is a leader in Contact Center Solutions, specializing in BPOaaS, AI Technology, CX Services, Business Intelligence, Data Analytics, and QA Professional…”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 761 quality assurance companies for contact centers worldwide

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Quality assurance companies for contact centers worldwide at a glance

As of Sep 29, 2026
10.2%Verified-email coverage
31.5Average contacts per company
11-50Median size (employees)
2.0%Largest-city concentration · Sao Paulo
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
289
11-50
211
51-200
142
201-500
59
501-1,000
27
1,001-5,000
28
5,001-10,000
2
10001+
2

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 quality assurance companies for contact 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
Every country. Country and city lists for quality assurance companies for contact centers are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “quality assurance companies for contact 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 quality assurance companies for contact 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 quality assurance companies for contact 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, 2,434 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.

Quality assurance companies for contact centers by location

4 lists · largest first

Every Quality assurance companies for contact centers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

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 quality assurance companies for contact 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 quality assurance companies for contact centers are there worldwide?

RevenueBase identified 761 quality assurance companies for contact 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?

American Call Center, headquartered in Guayaquil, tops this list with the largest team on record.

Which country has the most quality assurance companies for contact centers?

The United States leads with 144 companies, followed by Brazil (39) and India (36). Every quality assurance companies for contact centers list by country and city is linked on this page.

Which city has the most quality assurance companies for contact centers?

Sao Paulo leads with 15 headquartered companies, followed by Madrid (7) and Santiago (7).

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 2,434 verified decision-maker contacts tracked across these 761 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.