Like many people, I make extensive use of discount telcos to cut the cost of my still quite large telecoms bill, especially on calls to mobiles.
Calls to mobiles are expensive, mainly because the cellcos impose a mobile termination charge - usually 4/5p a minute - on landline calls terminating on the mobile network.
A number of discount telcos - as well as businesses - make use of a device known as a SIM gateway, also known as Premicell.
Basically these are mobile phone-like boxes with a BT-style phone socket on the side that allow a PABX or even a cordless phone to make outgoing calls across the mobile network.
With some cellcos selling 1000 minutes for £30.00 a month or less (without a handset) , it doesn't take a mathematical genius to realise that the costs of calling a mobile can be slashed in this way.
The cellcos aren't too happy with these boxes and their users, as they reckon they're losing revenue. And they're right.
Now a new company called Revector is working with the cellcos to track down users of these SIM gateways using a network of robot calling boxes.
According to Revector, over the past year, more than 100,000 unique SIM cards used by GSM Gateway operators around the world have been identified.
Revector claims that losses vary extensively from one GSM operator to another, but with a revenue loss of about five quid per SIM per day, the `losses' are mounting up.
Revector's aim is to stamp out usage of these SIM gateways and Premicells generally. Can it do it? I doubt it, as we're in a legal and contractual grey area here, but the cellcos are reserving their right to terminate a contract where they suspect a SIM card is being used in a gateway product.
Which, of course, means that pricing on calls to mobiles via discount telcos will creep up. Next time you get your office or home phone bill, you may care to think of Revector and what this company does...