Below are some links relating to parental controls and internet safety from the main internet and phone network providers.
Virgin http://www.virginmedia.com/shop/broadband/parental-control.html
O2 http://parentalcontrols-on.org/O2
EE http://ee.co.uk/help/safety-and-security/security/content-lock-and-orange-safeguard
Three http://parentalcontrols-on.org/3
BT http://bt.custhelp.com/app/answers/detail/a_id/46768/~/bt-parental-controls—how-to…-guide
Vodaphone http://parentalcontrols-on.org/Vodafone
Giffgaff https://community.giffgaff.com/t5/Blog/Internet-Safety-and-Parental-Controls/ba-p/2696285
Sky https://www.sky.com/help/articles/parental-controls-sky-mobile?topic=managing-settings
PlusNet https://www.plus.net/help/broadband/how-to-use-plusnet-safeguard/
TalkTalk http://parentalcontrols-on.org/TalkTalk
Web Sites