Licensed software. You run the bill analysis and inventory management software on premises. The vendor provides the normalized billing data from all your carriers so you don't have to manage its translation to the analysis tool's standard, and you can tap into the vendor's pricing database to analyze your costs versus industry norms. Providers include AnchorPoint, Asentinel, Avotus, MBG, MDSL, Paetec, Quickcomm, Rivermine, Symphony, Tangoe and UTR Global.

Joint management using on-demand software. The vendor hosts the software (instead of just handling the data), customizes reports and handles routine analysis, so you can focus on exceptions to your billing expectations, service-level agreements and provisioning plans. Main players are the same firms noted above for licensed software.

Managed service. The vendor handles everything except the payment approval, although you have online access to the vendor's data and reports for monitoring and analysis. The main choices are AnchorPoint, Avotus, Cass Information Systems, Control Point Solutions, MBG, ProfitLine, Symphony, TnT Expense Management, UTR Global and Vercuity. Mid-market specialists include Amtel, Broadsource, Comstructure, Creative Cost Management, Invoice Insight, MTS, ParseLogic, and Tele-Razor Technologies.