From Thursday the cost of Chargecard calls made within the UK more than doubled to 20p a minute, after Oftel, the telecommunications regulator ruled that previous prices discouraged competition.
Millions of people now have BT Chargecards, and they have become particularly popular for parents to give to students who are about to go off to college. The cards allow callers to key in a code and have the cost of the call automatically debited to a home telephone account.
The marketing drive to students, backed up by television advertising and promotional literature, is one that universities are happy to co-operate with: phones that are cashless have obvious advantages in shared accommodation.
But parents should be warned. Chargecard calls from anywhere in the UK have a minimum charge of 9.5p, but now cost 20p a minute, whatever the time of the day or week. For a weekend call of 20 minutes, when UK rates are lower and when students are most likely to phone home, even a reverse- charge call, with its pounds 1.80 fixed charge, would be cheaper. And it is almost certainly cheaper to get your children to use their cash, or even supply them with pre-paid cards.
The cost of peace of mind, even before these price rises, was high, and it is not something that BT has been keen to advertise. How many parents know that, even before the price rise, calling by chargecard was significantly more expensive than calling your offspring back. Very few, judging by my own straw poll. The common assumption is, as one parent put it: "As it was being charged to our account, it was billed at the same rates." This conclusion is not surprising since BT has promoted the service as "Dialling direct with your BT Chargecard can save you money".
It can take some time to discover the true costs. For me, it was when my daughter, in Israel for a year before university, phoned to say that she had been told that she could not use her chargecard as her 15-minute call the day before had taken her over her weekly pounds 35 limit.
We had, it is true, been shocked by the last chargecard bill: the pounds 231 total for her calls home swiftly dispelled any idea that we would save money when our loquacious teenage daughter left. While she had not apparently spent much time on the phone, our suspicions had not been aroused. But this pounds 35 plus call demanded investigation. It was no mistake. That is when I discovered that, with rates of pounds 2.18 a minute from Israel on chargecard, I was paying more than twice as much as if we had called her straight back. I worked out our last phone bill would have been pounds 150 lighter had we done so. When I put this to BT I was told: "It's all clear on the list of charges."
It wasn't. The comparison given, with an operator-connected call, made a chargecard call look cheap.
But direct-dialled calls were not included in the table. The spring edition of Update, the BT promotional leaflet, proclaimed: "Dialling direct with your BT Chargecard can save you money." It was no wonder we had not realised the true cost.
Chargecards may not save money in hotels, either. One person in a Munich hotel discovered after making all calls on chargecard that he still got a pounds 50 bill from the hotel. While that is a reflection on hotel phone charging policies, rather than chargecard, it shows the hidden dangers in the scheme.
Clear information about charges is the responsibility of BT Chargecard. When we ran the company's freephone helpline to increase the weekly limit for our daughter because, as we explained, she was moving to Israel, it would have been nice to have had proper advice that included comparisons.
Though chargecard is convenient, and may have its place in an emergency, the cost of using it may well outweigh the advantages, particularly after the price increases for UK calls (international rates remain unchanged).
Previous complaints to BT about charge information being misleading were met with this response: "Our chargecard charges," said a BT spokesman, "are well publicised." It will be interesting to see whether over the next few weeks that is the case with the new, higher prices.