Telstra's BlackBerry customers may be cut off

Shopping around for the best mobile plan can be a good way to get yourself familiar with the market, finding out which suppliers are available and what services they offer both individually and as an industry.

But be aware that changes to networks and consequent service interruptions and cancellations do happen, unpredictably and irrevocably.

In many cases the phone company will be unaware of the change, or unable to notify customers before the terms of their contracts are finalised.

BlackBerry users may be in a situation involving reduced or terminated coverage later this year, with Telstra planning to end an agreement which controls the operation of its 3G service at the end of July, according to a report in The Age.

From August, Telstra's 3G will run through the Next G network, which utilises a different frequency from Hutchinson's 3 network, currently used by some BlackBerry devices.

According to The Age, users most at risk of being affected by the change are those who purchased their BlackBerry from another company, then switched their account to Telstra.

One businessman said that his company would be affected to the tune of $20,000 by the change, due to replacement phone costs.

A Telstra spokesperson told the publication that training had been carried out with staff, so new customers would be warned about the change.