Virgin Trains is shaking up its timetable to give cheaper tickets for passengers heading south to London as well as new destinations which will link Glasgow with Coventry and Milton Keynes.
Rail chiefs say the overhaul means better deals for passengers.
At the moment Virgin Trains takes passengers from Scotland's biggest city to London as well as Birmingham.
From next week the Birmingham service is being extended to London Euston.
That will also include calling at the Birmingham International station which lies close to the local airport.
Passengers who are not in a rush can pocket savings. Cheap fare deals will be on offer to those who buy a ticket for London Euston via Birmingham. The journey is an hour longer than the other direct Glasgow-London route but Virgin hope it will appeal to "leisure travellers" and "price sensitive passengers."
Glasgow passengers will also be able to get a train direct to Coventry and Milton Keynes as part of Virgin's plans to boost its Ango-Scottish timetable with the improvements beginning on Sunday.
There will also be extra capacity. More than 3000 extra seats are being added to cross border services every weekday when most Super Voyager trains will have 10 carriages - double the existing five cars - while the Pendolinos will be increased for nine to 11 carriages.
Gary Iddon, general manager for Virgin Trains for Scotland. said: "This new capacity will allow us to continue the growth we've seen. From winning the West Coast passenger franchise in 1997, we've transformed a loss-making service into the country's best-loved long-distance operator.
"This is the biggest change we have made since we revolutionised West Coast services with the Virgin High Frequency timetable in 2009 and creates a number of new, direct journeys to key locations south of Birmingham.
"The step-change in capacity is a sign of the confidence we have that there is more growth in the route and more that we can do to get passengers out of cars and planes and on to our services."
Passenger numbers running between Glasgow and Birmingham have soared by 261% since 2008 with Virgin chiefs claiming the introduction of more seats represents an increase of almost 80%.