(Pocket-lint) - Virgin Media has started contacting customers who have used Wi-Fi on the London Underground asking them to sign up or face having to pay when the service stops being free in January.
"Free WiFi has been a huge success on the London Underground. In fact, since it launched, over 800,000 people have been tweeting and emailing underground." Virgin Media tells us.
The company confirms that a further 48 Wi-Fi-enabled stations will be added by next spring, 20 of which will go live before the end of the year.
However the service that has been free over the summer won't be for much longer unless you are a Vodafone, EE, or Virgin Media customer.
Vodafone and EE customers (that includes Orange and T-Mobile users as well) will have to sign up to their operator's Wi-Fi services to benefit.
Virgin Mobile, Virgin Media, and Virgin Broadband customers can sign up here.
Travellers who aren't customers of Vodafone, EE, or Virgin Media will have to by a Wi-Fi Pass to use the service from February. Virgin Media has let to detail how users will be able to do that or how much it will cost.