Vonage(R) Introduces TCS VoIP Verify(TM)

Market Wire, September, 2005

TeleCommunication Systems (TCS) (NASDAQ: TSYS), a global leader in mission critical communications, today announced that Vonage, a leading provider of broadband phone service, is the first Voice-over Internet Protocol (VoIP) service provider to utilize TCS' recently introduced VoIP Verify(TM) service. Designed for mobility, VoIP Verify provides Vonage subscribers with a simple tool to determine the availability and extent of the individual's emergency services coverage from the caller's current registered location.

When Vonage customers dial 9-3-3 from their Vonage service, VoIP Verify informs the user how his or her distress call will be routed, and what information the Vonage user should be prepared to provide to the emergency services call taker. Offering subscribers the ability to hear verification of their 9-1-1 coverage status at any time simply by placing a VoIP call demonstrates Vonage's continuing determination to provide its subscribers with a comprehensive solution set for their emergency services needs.

"Vonage is implementing broad measures to ensure our subscribers' personal safety," said Martin Hakim Din, Senior Vice President, Architecture, Vonage Network, a subsidiary of Vonage Holdings Corp. "We believe that Vonage callers should know where their call will go and how it will be handled when they have an emergency. By dialing '9-3-3,' Vonage customers will know what kind of emergency response services they will get. We selected TCS to deliver this life-saving solution using its VoIP Verify service, because of its proven experience in the routing and delivery of wireless E 9-1-1 calls and shared commitment to public safety."

Vonage is currently rolling out E9-1-1 services to PSAPs across its national footprint. Based on the combination of the user's location and current VoIP E9-1-1 deployment status of the PSAP to which their 9-1-1 call would be routed, a message is generated that informs the caller of his or her current emergency service status. A basic requirement for E9-1-1 service is that VoIP users must "provision" or register the location address of the device that may be used for a 9-1-1 call. If the provisioned location is supported by the local PSAP, callers will be informed that they are in an area where calls for emergency services can be delivered to the local PSAP for response and action. TCS VoIP Verify puts this information literally at the fingertips of Vonage's subscribers.

"People need to know if their VoIP phone will provide them with 9-1-1 coverage. One of the most compelling features of Vonage's service is its mobility; making and receiving calls wherever users can access Vonage's service. By delivering VoIP Verify, Vonage and TCS believe we are exceeding customers' expectations by providing additional comfort anytime, anywhere as to how they can access emergency services," said Drew Morin, Senior Vice President and Chief Technology Officer for TCS.

ABOUT VONAGE®

Vonage has pioneered the broadband phone industry, setting the standard for pricing, features, call quality and reliability for the entire VoIP category. Vonage's award-winning service is sold on the web and through national retailers like SAM's Club, RadioShack, Best Buy, Circuit City, Staples, Fry's Electronics, Office Depot and CompUSA. Vonage Holdings Corporation is headquartered in Edison, New Jersey. For more information about Vonage's products and services, please visit http://www.vonage.com or call 1-VONAGE-HELP. Vonage® is a trademark of Vonage Marketing, a subsidiary of Vonage Holdings Corp.

ABOUT TELECOMMUNICATION SYSTEMS, INC.

TeleCommunication Systems, Inc. (TCS) (NASDAQ: TSYS) is a leading provider of mission critical communications to carriers, enterprise and government customers. TCS' wireless data offerings include location-based Enhanced 9-1-1 services, messaging and location service infrastructure for wireless operators, real-time market data and alerts to financial institutions, mobile asset management and mobile office solutions for enterprises, and encrypted satellite communications to government customers. For more information visit www.telecomsys.com.

This announcement contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities and Exchange Act of 1934, as amended. These statements are based upon TCS' current expectations and assumptions that are subject to a number of risks and uncertainties that would cause actual results to differ materially from those anticipated.

The actual results realized by the Company could differ materially from the statements made herein, depending in particular upon the risks and uncertainties described in the Company's filings with the Securities and Exchange Commission (SEC). These include without limitation risks and uncertainties relating to the Company's financial results and the ability of the Company to (i) reach and sustain profitability as early as anticipated, (ii) continue to rely on its customers and other third parties to provide additional products and services that create a demand its products and services, (iii) conduct its business in foreign countries, (iv) adapt and integrate new technologies into its products, (v) expand its business offerings in the new wireless data industry, (vi) develop software without any errors or defects, (vii) protect its intellectual property rights, and (viii) implement its sales and marketing strategy.