Sky is being investigated by the communications regulator following complaints that customers are unable to cancel at the end of their contract.
Ofcom has launched the investigation into Sky's TV, phone and broadband services after monitoring the way providers across the board give customers opportunities to cancel their contracts.
It has also been looking at patterns in complaints. The Telegraph has previously reported that it's received a number of complaints from Sky customers whose subscription remained in force despite cancelling.
But rules overseen by the regulator mean providers must not make it difficult for customers to leave a contract when they have a right to. See MoneySavingExpert.com's Cheap Broadband guide to find the best deal for you if you're thinking of switching.
Ofcom will now look at whether Sky's procedures for cancelling acts as a disincentive for customers wanting to switch, and whether there have been any breaches of customers' termination rights. It can't say how long the investigation will last, but they tend to be between six and nine months.
I'm a Sky customer. How do I cancel?
Customers who are out of their minimum term can cancel Sky TV penalty free by giving a minimum 31 days' notice, while Sky Broadband and Sky Talk customers need to give a minimum 14 days' notice.
Sky says it clarified its cancellation process last year, so if you want to leave, call it on 03332 022 135 (this is free for Sky Talk customers and costs the same as calling an 01 or 02 number if you're not a Sky Talk customer).
Alternatively you can use its Live Chat option (available from 8.30am –8pm everyday) to speak directly to an adviser online, or send a letter or email telling Sky you want to cancel and it'll call you back to verify your details and process the request.
For more information on how to change or cancel a Sky package, see Sky.com.
A Sky spokesperson says: "We're committed to delivering the best service in the country and we believe this is one of the reasons why more customers than ever are choosing Sky. We will work closely with Ofcom to help them with their investigation".
Got a gripe about your provider? Complain
Ofcom can't investigate individual complaints – it collates complaints to see any trends before deciding which issues or providers to investigate.
But if you feel you've been treated unfairly, contact your provider to complain. You can use our free online Resolver complaints tool to help you do this.
If you don't get anywhere going directly to the company involved, you can take your complaint to the relevant ombudsman service to look into. See our How to Complain guide for more on which ombudsman service is best.
Additional reporting by the Press Association.