If you're a Vodafone customer, you need to check your bills today, to make sure you're not paying £12 a year for a service that you know nothing about.
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The charge could be hitting anyone who has taken out a new contract since February. When they signed up for a contract, they were given a free three-month trial to 'Secure Next', which is designed to protect them against malware, viruses and scams when they use their smartphone to go online.
The problem is that some customers weren't aware of the trial, which means they didn't realise they had to cancel it before the end of the three months in order to prevent the £1 a month charge. Those customers are being charged £1 a month for a service they may know nothing about.
According to a report in the Daily Mail, while the service was in promotional material, the cost isn't in the small print of the contract if you signed up online, and some customers said when they took out a contract in store, staff didn't warn them about the service or the potential to be charged if they didn't cancel it.
What can you do?
The first step is to check your bill, where you should see a charge for Secure Net if you're paying it. According to Vodafone, 70% of people have kept the service after the end of the free trial, so will be paying for it.
If you are paying £1 a month, and you don't want the service, you can get in touch with Vodafone to cancel it. The company told the Daily Mail it would refund any customers who had been unaware they were paying for the service, so it's worth checking whether you can get any charges refunded too.
It's a useful reminder that it's always worth checking bills. Nowadays many of them arrive online, and require you to click through into your account and enter passwords in order to see your bill - rather than just opening a letter. The hassle factor puts people off, but checking your bill is the only way to be sure what you are paying, and what you are receiving in return.
A new uSwitch report, for example, revealed that energy firms have wrongly charged households over £100 million due to billing mistakes - and the average costumer is due a refund of £79. Mistakes included companies that didn't reflect a meter reading sent by a customer, those that added totals incorrectly, and some that applied the wrong tariffs.
Checking your bills is a headache that many people try to dodge, but if you can spare a few minutes each month you can keep on top of what you are paying for your services, check for mistakes, and even end up with a refund into the bargain.