Operator of rail services in the UK. Most of these provide passenger services. Click a title for a list of routes. Please let me know if any of these contain errors, or if I've missed anything.

• Alphaline Regional Railways
• Anglia Railways Train Services
• Cardiff Railway Company
• Central Trains Limited
• Chiltern Railways
• Connex
• Docklands Light Rail
• Eurostar
• English Welsh and Scottish Railways
• First Great Eastern
• First Great Western
• First North Western
• Gatwick Express
• Great North Eastern Railway (GNER)
• Heathrow Express
• Island Line
• London Transport
• LTS Rail
• Merseyrail Electrics
• Midland Main Line
• NI Railways
• Northern Spirit
• Scotrail Railways
• Silverlink Train Services
• South West Trains
• Thameslink Rail
• Thames Trains
• Virgin Trains
• WAGN
• Wales and West

Sources: Railtrack and www.rail.co.uk