The company said it intends to add CallVisions features to the VeriSign Commerce Suite, which handles the complex task of billing for phone calls and, in the case of cell phones, for wireless downloads.
The $30 million purchase of CallVision, expected to close in the next few weeks, is a "strategic investment," VeriSign Executive Vice President Vernon Irvin is quoted as saying in a news release.
A VeriSign spokesperson had no immediate additional comment.
CallVision, competitor eDocs Inc. and a plethora of other customer self-care specialists aim to help telephone and broadband operators keep customers from getting fed up with the complexities of their bills.
Making customers happy builds up their loyalty to the company, and keeps them from switching to competitors.
CallVision is the second company catering to online phone billing and customer self-service to be purchased recently. Business software and applications provider Siebel Systems Inc. bought eDocs in late 2004.
Since July 2005, VeriSign has purchased at least three companies, including intelligence specialist iDefense, which VeriSign said it bought for $40 million in cash, and Weblogs.com, a ping service considered vital to the blogging world.
Financial details of the Weblog.com deal were not disclosed.