Company lists · Data refreshed November 2026

Top 25 Inside sales outsourcing firms worldwide

Name: Inside sales outsourcing firms worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Nov 5, 2026 14,661 companies tracked

RevenueBase identified 14,661 company matches for inside sales outsourcing firms worldwide as of November 2026 and tracks 215,538 professional contacts across them, including 20,856 with verified work emails. The United States is the largest market and London the largest hub.

This list covers company matches for inside sales outsourcing firms worldwide, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 5, 2026. Country and city lists for inside sales outsourcing firms follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Nov 5, 2026 How this list was built

14,661Companies

215,538Contacts tracked

20,856Verified emails

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The 25 largest inside sales outsourcing firms worldwide

Ranked by team size

Top 25 of 14,661 company matches for inside sales outsourcing firms worldwide, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 5, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	Emtelco S.A	Exact match	Medellín, ColombiaHQ recorded Nov 5, 2026	10001+	6,207 contacts →
	Exact match “Maximizamos el valor de cada contacto de las empresas con sus clientes, gestionando los procesos de relacionamiento a través de canales tefónicos, virtuales y presenciales.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
2	Marketsource INC	Exact match	Alpharetta, GA, United StatesHQ recorded Nov 5, 2026	5,001-10,000	3,613 contacts →
	Exact match “MarketSource, an Allegis Group company, is a sales acceleration company focused on delivering better outcomes for many of the world’s most iconic brands.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
3	Stream Global Services	Exact match	Eagan, BC, United StatesHQ recorded Nov 5, 2026	10001+	3,230 contacts →
	Exact match “Stream Global Services is a premium business process outsource (BPO) service provider specializing in customer relationship management solutions including sales, customer care…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
4	Advanced Call Center Technologies, LLC	Exact match	Berwyn, PA, United StatesHQ recorded Nov 5, 2026	5,001-10,000	3,116 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
5	Marketstar	Exact match	Ogden, United StatesHQ recorded Nov 5, 2026	1,001-5,000	2,619 contacts →
	Exact match “MarketStar is a global B2B sales outsourcing leader with 38+ years of experience driving predictable revenue growth.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
6	Allied Global	Exact match	Des Moines, IA, GuatemalaHQ recorded Nov 5, 2026	5,001-10,000	2,152 contacts →
	Exact match “Regardless of your Company’s size (from Start-ups to Fortune 500), business vertical or service requirements, we act as a seamless extension of your team to help you grow, and…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
7	Webhelp Enterprise	Exact match	Paris, FranceHQ recorded Nov 5, 2026	10001+	1,824 contacts →
	Exact match “The Concentrix B2B sales practice is here to design, build and run projects for our clients.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
8	Full Potential Solutions	Exact match	Waltham, United StatesHQ recorded Nov 5, 2026	1,001-5,000	1,563 contacts →
	Exact match “Full Potential Solutions (FPS) is a new kind of performance-based outsourcing firm that puts culture and employees first, because we believe that happy, fulfilled teams accomplish…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
9	The Office Gurus	Exact match	St Petersburg, RussiaHQ recorded Nov 5, 2026	1,001-5,000	1,318 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
10	Information Evolution, INC	Exact match	Austin, TX, United StatesHQ recorded Nov 5, 2026	501-1,000	1,297 contacts →
	Exact match “We are a boutique outsourcing firm specializing in keeping our customers' databases up-to-date, accurate, and as robust as possible.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
11	crystel.co	Exact match	Amman, JordanHQ recorded Nov 5, 2026	1,001-5,000	1,223 contacts →
	Exact match “Crystel emerged as a leading Outsourcing Service Provider (OSP) since its establishment in Jordan in early 2007.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
12	Transparent BPO	Exact match	Rockville, United StatesHQ recorded Nov 5, 2026	1,001-5,000	1,135 contacts →
	Exact match “Transparent BPO was founded to provide its clients with superior nearshore contact center services and business process outsourcing at competitive pricing.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
13	B2s Business Support Services	Exact match	Gennevilliers Cedex, FranceHQ recorded Nov 5, 2026	10001+	1,087 contacts →
	Exact match “Expert de la relation client depuis 1996, b2s est le N°1 de l’externalisation de votre relation client en qualité délivrée.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
14	Horatio	Exact match	Santo Domingo, United StatesHQ recorded Nov 5, 2026	1,001-5,000	1,027 contacts →
	Exact match “Horatio is a premier, tech-enabled outsourcing partner helping ambitious companies scale customer experience and complex business operations without compromising quality…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
15	Inktel Contact Center Solutions	Exact match	Doral, FL, United StatesHQ recorded Nov 5, 2026	1,001-5,000	969 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
16	Answernet	Exact match	Horsham, PA, United StatesHQ recorded Nov 5, 2026	501-1,000	946 contacts →
	Exact match “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!” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
17	Servestsa	Exact match	Caracas, VenezuelaHQ recorded Nov 5, 2026	n/a	903 contacts →
	Exact match “Statistics first” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
18	CPM International	Exact match	Thame, United KingdomHQ recorded Nov 5, 2026	10001+	901 contacts →
	Exact match “CPM is an international sales outsourcing and customer experience agency.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
19	ZAZ Vendas	Exact match	Campinas, BrazilHQ recorded Nov 5, 2026	501-1,000	874 contacts →
	Exact match “Em um mercado cada vez mais competitivo, onde a eficiência em vendas massificadas e externas é um desafio constante, a ZAZ Vendas surge como a resposta definitiva.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
20	Sequential Technology International	Exact match	Bethlehem, United StatesHQ recorded Nov 5, 2026	1,001-5,000	811 contacts →
	Exact match “Sequential Tech is the trusted outsource partner of wireline/wireless telecommunication, broadband, cable/MSO, and satellite service providers.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
21	Talksure	Exact match	Durban, South AfricaHQ recorded Nov 5, 2026	501-1,000	740 contacts →
	Exact match “Established in 2010, Talksure has developed a reputation for being a respected financial services provider and outsource business services partner.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
22	Abstrakt Marketing Group	Exact match	St. Louis, MO, United StatesHQ recorded Nov 5, 2026	501-1,000	732 contacts →
	Exact match “We book the qualified meetings that fill your pipeline for any B2B company ready to grow.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
23	Salebuild	Exact match	Redwood City, CA, United StatesHQ recorded Nov 5, 2026	n/a	725 contacts →
	Exact match “Salesify, a leading provider of B2B demand generation services, helps our clients create pipeline and accelerate revenue by identifying, profiling, nurturing and connecting with…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
24	DMF Sales&marketing	Exact match	Asnières Sur Seine, FranceHQ recorded Nov 5, 2026	201-500	708 contacts →
	Exact match “MISSION DMF sales and marketing est un des tous premiers prestataires d’externalisation commerciale en France.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
25	Girnar Care	Exact match	Jaipur, IndiaHQ recorded Nov 5, 2026	501-1,000	681 contacts →
	Exact match “We at Girnar Care work towards customer satisfaction and it is also a center of customer excellence.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “inside sales outsourcing firms”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 14,661 inside sales outsourcing firms worldwide

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Inside sales outsourcing firms worldwide at a glance

As of Nov 5, 2026

9.7%Verified-email coverage

14.7Average contacts per company

11-50Median size (employees)

2.0%Largest-city concentration · London

Nov 5, 2026Page data refreshed

Companies by employee count

1-10

7,228

11-50

4,626

51-200

1,879

201-500

563

501-1,000

183

1,001-5,000

5,001-10,000

10001+

Email recency is reported on each country list linked below.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
Coverage: Every country. Country and city lists for inside sales outsourcing firms are linked below.
What qualifies: Company records worldwide whose business descriptions match “inside sales outsourcing firms” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch: Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview: The public preview omits records without a verified work email. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality: RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 20,856 professional contacts with verified work emails across the full matched dataset. 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 November 5, 2026. Lists refresh periodically as the graph is re-checked.
Record context: Company records and descriptions can change. Check the company's website for its current services and locations.

Inside sales outsourcing firms by location

78 lists · largest first

Every Inside sales outsourcing firms 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 SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “inside sales outsourcing firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many inside sales outsourcing firms are there worldwide?

RevenueBase identified 14,661 company matches for inside sales outsourcing firms worldwide as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Emtelco S.A tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which country has the most inside sales outsourcing firms?

The United States leads with 2,955 companies, followed by India (1,254) and the United Kingdom (926). Every inside sales outsourcing firms list by country and city is linked on this page.

Which city has the most inside sales outsourcing firms?

London leads with 300 company records, followed by Pune (211) and Lahore (160).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 20,856 professional contacts with verified work emails tracked across these 14,661 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 5, 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 SmartSearch, 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.