What departments does Callsign have?

Callsign has employees across 15 departments including Finance, Military & Protective Services, Engineering, Operations, Information Technology.

What is the largest department at Callsign?

The largest department at Callsign is Engineering with 6 employees.

Where are Callsign employees located globally?

Callsign has employees across 4 continents and 16 countries including South Africa, United Arab Emirates, India, Philippines, Singapore.

How has Callsign's team size changed over time?

Callsign's team has decreased from approximately 302 to 209 employees based on available data.

Learn more at LeadIQ.com

Callsign Employee Directory

Q: Who are Callsign's key employees and leadership?

Callsign's key employees include: Chairman & Ceo: Z. H., Chief Revenue Officer: L. C., Chief Information Officer: A. P., Chief Revenue Officer: S. O., Chief Security Officer: I. C. C..

Computer and Network SecurityEngland, United Kingdom201-500 Employees

Callsign is a London, England, United Kingdom-based company in the computer and network security industry, employing between 201 and 500 people. It develops digital-trust solutions that mimic human identification to distinguish genuine users, aiming to provide privacy and security with minimal friction while blocking bad actors. The company reports that its user recognition can reach up to 99.999% accuracy. It has formed partnerships with Visa in 2023 and with State Talking in 2026, and was named a Leader in Product Vitals in Javelin Strategy & Research's 2024 Authentication and Identity-Proofing Vendor Solutions Scorecard. Reported revenue is in the range of $25 million to $50 million, and its technology stack includes Zipkin, Continuous Delivery, XML, DocuSign, Microsoft Office, Ruby, Scala, and Google Tag Manager.

Callsign Global Highlights

Europe
180

United Kingdom Of Great Britain And Northern Ireland
173
Sweden
4
Ireland
1
Italy
1
Switzerland
1

Asia
73

United Arab Emirates
47
India
12
Pakistan
8
Philippines
2
Singapore
1
Malaysia
1
Indonesia
1
Saudi Arabia
1

North America
15

United States Of America
14
Canada
1

Africa
1

South Africa
1

Callsign's Leadership

L. C.
Chief Revenue Officer
Mobile Phone
Email
A. P.
Chief Information Officer
Mobile Phone
Email
S. O.
Chief Revenue Officer
Mobile Phone
Email
I. C. C.
Chief Security Officer
Mobile Phone
Email
G. W.
Chief Financial Officer
Mobile Phone
Email
S. M.
Chief Technology Officer
Mobile Phone
Email
C. T.
Chief Of Staff
Mobile Phone
Email
C. H.
Vp Of Integration Strategy
Mobile Phone
Email

Callsign Employee Metrics

100%

50%

2026

2025

Engineering
Operations
Analytics
Consultant
Product Management
Other
Program & Project Management
Supply Chain
Solutions Engineering
Information Technology
Administrative
Research
Information Security

Contact profiles from Callsign

Name

Title

Contact Info

Location

Last Update

L. C.
Chief Revenue Officer
Mobile Phone
Email
United StatesNew York
Apr 16, 2026
S. G.
Senior People Partner
Mobile Phone
Email
Jun 03, 2026
A. P.
Chief Information Officer
Mobile Phone
Email
Jul 29, 2025
Z. H.
Chairman & Ceo
Mobile Phone
Email
United Kingdom
Jul 24, 2025
S. O.
Chief Revenue Officer
Mobile Phone
Email
United KingdomEngland
Apr 08, 2026
I. C. C.
Chief Security Officer
Mobile Phone
Email
United Kingdom
Apr 17, 2026
G. W.
Chief Financial Officer
Mobile Phone
Email
United KingdomEngland
Apr 08, 2026
S. M.
Chief Technology Officer
Mobile Phone
Email
Ireland
May 11, 2026
I. W.
Co-Founder & Chief Operating Officer
Mobile Phone
Email
United KingdomEngland
Sep 09, 2025
E. W.
Senior People Partner
Mobile Phone
Email
United KingdomEngland
Feb 15, 2025

Frequently Asked Questions

What is Callsign known for?

Callsign was founded in 2011 operates in the Computer and Network Security industry. The company's main headquarters is located in London, England United Kingdom; you can contact the main corporate office by phone at

+1-571-966-****

. Explore Callsign's company overview page for more information.

What is Callsign's most common email format?

Callsign employees' email format typically follows the pattern of . Trying to find reliable and up-to-date employee contact data? Find more Callsign email formats with LeadIQ.

How many employees does Callsign have currently?

Callsign has approximately 274 employees as of May 2026. These team members are located across 4 continents, including EuropeAsiaNorth America.

Who are Callsign's key employees and leadership?

As of May 2026, Callsign's key employees include:

Chief Revenue Officer: L. C.
Chief Information Officer: A. P.
Chief Revenue Officer: S. O.
Chief Security Officer: I. C. C.
Chief Financial Officer: G. W.

Looking for contact data? Unlock accurate emails and phone numbers for your ideal prospects with LeadIQ.

Everything for prospecting,
in one platform.

What you can expect from LeadIQ:

B2B data verified in real-time
Sync data to your CRM, & add it to an outreach sequence in one click
Integrations with your tech stack for optimal efficiency
A patented AI cold email generator
Account & contact-level job change tracking

Ready to create more pipeline?

Get a demo and discover why thousands of SDR and Sales teams trust
LeadIQ to help them build pipeline confidently.

Callsign Employee Directory

Find Callsign employees' phone numbers or email addresses

Name search is limited — try advanced search instead