What to do if you smell gas - https://www.energynetworks.org/keeping-you-safe/smell-gas
Cadent Gas Limited are a Gas distribution network operator delivering gas to around 11 million consumers - https://cadentgas.com/Home
The following site includes links to all electricity network operators - https://www.energynetworks.org/campaigns/thinkbeforeyoudig
Who is my network operator - http://www.energynetworks.org/
The UK Health and Safety Executive advice and guidance - http://www.hse.gov.uk/pipelines/
DNV support Cadent Gas Limited to protect their assets from harm https://www.dnv.com/software/software-services/maps-viewer.html