Picking a telecom expense management vendor isn't easy. After all, there are a 100 or more of them in North America alone, and none is public, making it difficult to peer into their financials.

Not only is the market crowded, but there are multiple delivery models for TEM offerings. You can license software, buy it as a service or outsource your processes. No one model fits all customers, but analysts say you really need to know what you want before issuing an RFP.

So where to start? With this list. Based on our market knowledge, plus third-party research reports and interviews with analysts, customers and vendors, we've assembled this list of 10 TEM companies to watch.

Asentinel

Founded: 2002

Headquarters: Memphis

Leadership: CEO David Perdue, a 30-year veteran of the telecom industry who has founded a telecom service provider and a cellular company later sold to BellSouth.

What it sells: TEM Enterprise Integrations software (two-thirds of customers buy it this way) and software as a service. Software includes Real-time Auditing, Invoice Processing, Inventory/Order Management, Real-Time reporting and Worldwide modules.

Differentiators: The software not only audits bills, but automates the workflow and handling of them… It is one of the few North American TEM vendors that supports auditing, processing and reporting for bills from carriers outside the United States. Has a strategic partnership with CA for market referrals.

What others say: “They have a good strategy around enabling value-added networks and EDI feeds for automated TEM,” says Eric Goodness, Gartner research vice president. Customers tell Gartner they would like to see Asentinel improve its standard reporting capabilities and value-added professional services.

Cost: Depends on telecom spend, number of invoices and number of vendors a customer has. Asentinel says that on average, customers pay 1% to 3% of their annual telecom spend for its tools.

Potential savings: A 6% to 8% cost savings on erroneous telecom bills (80% of which are wrong according to some industry watchers). Larger companies might also see cost savings in labor reduction or reassignment once they automate their TEM operations. “Most customers will pay for the software in just a few months of using it,” Perdue says.

How company got started: In 2001, one of Cornerstone Technology Group’s clients, Union Planters Bank, asked the firm to write software that would better help them manage their $37 million telecom spend. Cornerstone produced that software, which is the basis for Asentinel’s software platform today. In 2002, Cornerstone brought the software to Perdue, who liked the idea of building a company around it. He ponied up his own cash and Asentinel was born.

Origin of company name: A derivative of sentinel, someone who stands guard.

Customers: Union Planters Bank, Fulton County, Ga., and Ticketmaster.

Funding: Entirely owned by its officers.