Company lists · Data refreshed September 2026

Top 25 Internal communications firms worldwide

RevenueBase identified 21,601 internal communications firms worldwide as of September 2026 and tracks 197,124 professional contacts across them, including 57,052 with verified work emails. The United States is the largest market and London the largest hub.

This list covers internal communications 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 20, 2026. Country and city lists for internal communications 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review
21,601Companies
197,124Contacts tracked
57,052Verified emails
Explore this list → Free signup · no credit card · 500 free credits

The 25 largest internal communications firms worldwide

Ranked by team size
Top 25 of 21,601 internal communications firms worldwide, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to internal communications firms: 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
1Partial evidenceNew York, NY, United StatesHQ checked Sep 20, 20265,001-10,0006,242 contacts →

Partial evidence

“Edelman is a global communications firm that partners with businesses and organizations to evolve, promote and protect their brands and reputations.”

Source: RevenueBase Database · checked Sep 20, 2026
2Partial evidenceNew York, United StatesHQ checked Sep 20, 20265,001-10,0003,541 contacts →

Partial evidence

“Burson is the global leader in communications, purpose-built to create value for our clients through reputation.”

Source: RevenueBase Database · checked Sep 20, 2026
3Indirect evidenceMumbai, IndiaHQ checked Sep 20, 20261,001-5,0001,920 contacts →

Indirect evidence

“Adfactors PR, founded in 1997, is India's largest Public Relations firm.”

Source: RevenueBase Database · checked Sep 20, 2026
4Indirect evidenceMadrid, SpainHQ checked Sep 20, 20261,001-5,0001,520 contacts →

Indirect evidence

“Together, we enhance and protect the value of your business.”

Source: RevenueBase Database · checked Sep 20, 2026
5Indirect evidenceNY, United StatesHQ checked Sep 20, 20261,001-5,0001,450 contacts →

Indirect evidence

“Hill & Knowlton is a strategic and creative partner to drive breakthrough opportunities for growth and value creation, advance corporate strategy, and build reputation capital and…”

Source: RevenueBase Database · checked Sep 20, 2026
6Partial evidenceRio De Janeiro, BrazilHQ checked Sep 20, 2026501-1,0001,277 contacts →

Partial evidence

“FSB Comunicações is an Integrated Communications agency focused on results.”

Source: RevenueBase Database · checked Sep 20, 2026
7Indirect evidenceHamburg, GermanyHQ checked Sep 20, 20261,001-5,000944 contacts →

Indirect evidence

“Scholz & Friends provides an all-inclusive selection of resources to assist client partners in sharing their stories and ideas.”

Source: RevenueBase Database · checked Sep 20, 2026
8Indirect evidenceNew York, NY, United StatesHQ checked Sep 20, 20261,001-5,000903 contacts →

Indirect evidence

“1300+ People.”

Source: RevenueBase Database · checked Sep 20, 2026
9Partial evidenceNew York, NY, United StatesHQ checked Sep 20, 2026501-1,000887 contacts →

Partial evidence

“Zeno Group is the fiercely independent and global, integrated communications agency, born from PR.”

Source: RevenueBase Database · checked Sep 20, 2026
10Partial evidenceNew York, NY, United StatesHQ checked Sep 20, 2026501-1,000821 contacts →

Partial evidence

“Porter Novelli is the strategic communications company, fueled by innovation, empowering clients to do business better in an ever-changing world.”

Source: RevenueBase Database · checked Sep 20, 2026
11Partial evidenceNew York, NY, United StatesHQ checked Sep 20, 20261,001-5,000815 contacts →

Partial evidence

“Ruder Finn is one of the world’s largest global independent integrated marketing and communications agencies, leading at the intersection of technology, human creativity, and…”

Source: RevenueBase Database · checked Sep 20, 2026
12Partial evidenceNew York, NY, United StatesHQ checked Sep 20, 2026201-500693 contacts →

Partial evidence

“ICR is a strategic communications and advisory firm that helps management teams align how they communicate with how markets think.”

Source: RevenueBase Database · checked Sep 20, 2026
13Indirect evidenceMadrid, SpainHQ checked Sep 20, 2026501-1,000623 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 20, 2026
14Partial evidenceSydney, AustraliaHQ checked Sep 20, 2026n/a621 contacts →

Partial evidence

“JIMJAM Ideas is an award winning integrated communications agency that believes CONNECTED IDEAS to be the key to powerful and transformative marketing.”

Source: RevenueBase Database · checked Sep 20, 2026
15Indirect evidenceNew York, NY, United StatesHQ checked Sep 20, 2026201-500543 contacts →

Indirect evidence

“Prosek Partners builds – and protects – the top brands in business.”

Source: RevenueBase Database · checked Sep 20, 2026
16Partial evidenceNew York, United StatesHQ checked Sep 20, 2026201-500482 contacts →

Partial evidence

“HUNTER is an award-winning, integrated marketing communications firm with offices in New York, Los Angeles, Chicago, and London and partnerships that extend our reach globally.”

Source: RevenueBase Database · checked Sep 20, 2026
17Indirect evidenceSão Paulo, BrazilHQ checked Sep 20, 20261,001-5,000471 contacts →

Indirect evidence

“Reputação é resultado.”

Source: RevenueBase Database · checked Sep 20, 2026
18Partial evidenceMumbai, IndiaHQ checked Sep 20, 2026501-1,000469 contacts →

Partial evidence

“MSL is Publicis Groupe’s public relations and integrated communications network, one of the world’s largest.”

Source: RevenueBase Database · checked Sep 20, 2026
19Indirect evidenceNew Delhi, IndiaHQ checked Sep 20, 2026201-500457 contacts →

Indirect evidence

“About Avian We.”

Source: RevenueBase Database · checked Sep 20, 2026
20Partial evidenceNew York, NY, United StatesHQ checked Sep 20, 20261,001-5,000449 contacts →

Partial evidence

“BCW is the global communications agency built to move people.”

Source: RevenueBase Database · checked Sep 20, 2026
21Strong evidenceOmaha, NE, United StatesHQ checked Sep 20, 202651-200447 contacts →

Strong evidence

“Workshop is a modern, purpose-built internal communications platform that helps teams create, send, manage, and measure employee communications in one place, starting with email…”

Source: RevenueBase Database · checked Sep 20, 2026
22Indirect evidenceSao Paulo, BrazilHQ checked Sep 20, 2026201-500441 contacts →

Indirect evidence

“Agência de comunicação full service com mais de 150 clientes nos segmentos corporativo, consumo, mídia e entretenimento, saúde, tecnologia e telecomunicações, dentre outros.”

Source: RevenueBase Database · checked Sep 20, 2026
23Partial evidenceAldgate, United KingdomHQ checked Sep 20, 2026201-500415 contacts →

Partial evidence

“Emperor is one of the UK's leading employee-owned creative communications agencies.”

Source: RevenueBase Database · checked Sep 20, 2026
24Indirect evidenceDelhi, IndiaHQ checked Sep 20, 2026201-500410 contacts →

Indirect evidence

“This is RepIndia.”

Source: RevenueBase Database · checked Sep 20, 2026
25Partial evidenceNew York, NY, United StatesHQ checked Sep 20, 2026201-500364 contacts →

Partial evidence

“Sunshine Sachs Morgan & Lylis is an independent, full-service firm specializing in communications and narrative strategy.”

Source: RevenueBase Database · checked Sep 20, 2026

Showing 25 of 21,601 internal communications firms worldwide

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 57,052 reachable decision-makers.

Free signup · no credit card

View the full list →

Internal communications firms worldwide at a glance

As of Sep 20, 2026
28.9%Verified-email coverage
9.1Average contacts per company
1-10Median size (employees)
2.7%Largest-city concentration · London
Sep 20, 2026Page data refreshed

Companies by employee count

1-10
15,602
11-50
4,943
51-200
789
201-500
151
501-1,000
44
1,001-5,000
30
5,001-10,000
4
10001+
5

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 internal communications 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 internal communications firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “internal communications 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 internal communications 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 internal communications 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, 57,052 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 20, 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.

Internal communications firms by location

105 lists · largest first

Every Internal communications 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 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 internal communications 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 internal communications firms are there worldwide?

RevenueBase identified 21,601 internal communications 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?

Edelman, headquartered in New York, tops this list with the largest team on record.

Which country has the most internal communications firms?

The United States leads with 4,394 companies, followed by Brazil (1,443) and the United Kingdom (1,341). Every internal communications firms list by country and city is linked on this page.

Which city has the most internal communications firms?

London leads with 587 headquartered companies, followed by Sao Paulo (446) and New York (395).

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 57,052 verified decision-maker contacts tracked across these 21,601 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 20, 2026.

Ready to reach these companies? Verified emails and direct dials for all 21,601 internal communications firms worldwide. Start with a free account, no credit card.

Download this list →

Related lists

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.