Toll fraud has long been a crime that enterprises have needed to watch out for and, unfortunately, using a VoIP system doesn't mean they can let their guard down. In fact, VoIP fraud can result in massive phone bills from the perpetrators of the crime making international calls — which can be devastating for small to medium-sized enterprises (SMEs).

And yet SMEs are most often the target of VoIP fraud as they are more likely to use poorly installed VoIP switchboards, according to Greg Massel, MD of VoIP solutions provider Switch Telecom, who added that this could put a small business out of business very quickly. "The business owner would be liable for those charges and most SMEs would find it very hard to recover from a phone bill that is perhaps ten times bigger than usual."

Switch Telecom's flagship VoIP product is a cloud-hosted PBX (News - Alert) switchboard that contains built-in safeguards, regularly updated security patches and suspicious activity notifications to help prevent VoIP fraud from occurring.

Generally, VoIP fraud is the result of cash-strapped smaller businesses looking to save even more money by hiring an under-qualified person to install their office PBXs. Poor installation can also lead to proper user names and passwords not being maintained, and security patches not being updated. Worst of all, if the person who installed the system leaves the company, there's often no one left with any knowledge at all of how to maintain it.

As such, the best way to avoid such a situation is to find an experienced VoIP provider.

The most common type of VoIP toll fraud is the calling of international premium numbers, which operate on a revenue-sharing basis. In such a situation, a portion of the call revenue goes to the company that owns the premium number, and so hackers will use a company's PBX system to call a number registered to a collaborator. The hacker receives a portion of the revenue and the business ends up footing the bill.

Such as scam resulted in AT&T (News - Alert) and T-Mobile losing $8 million.

In order to help reduce VoIP toll fraud, the Internet Service Providers' Association (ISPA) began holding a Voice Fraud Prevention Workshop which discusses strategies to combat the tactics used by VoIP fraudsters. However, at the end of the day, the best way to reduce the risk of fraud is to go with a professional when installing a PBX.