Virgin says Wi-Fi access will be available throughout the entire journey on the line, which runs from London Euston to Scotland, even when the trains pass through tunnels.
The service, which will be rolled out by mid-summer, will be free for first class passengers and T-Mobile Mobile Broadband customers. Standard class passengers will be charged £5 per hour of £10 for a day for a HotSpot pass. The pass can be purchased during the journey using any Wi-Fi-enabled device.
Graham Leech, executive director for Virgin Trains, said: "We're always looking at ways to improve the travel experience for our passengers so we're pleased to be able to answer their requests for access to the internet on our trains. We hope this latest improvement to our services will make travelling all the more enjoyable and productive for all our passengers.