Services on the East Coast Main Line will be brought back under public control on Sunday following the failure of the Virgin Trains East Coast (VTEC) franchise.
Trains on the vital route between London and Scotland will be run by the Department for Transport's (DfT) Operator of Last Resort, and branded as London North Eastern Railway (LNER).
The first LNER service will be the 7.54am departure from Newcastle to London King's Cross.
VTEC, a joint venture between Stagecoach (90%) and Virgin (10%), began operating in March 2015.
The firms agreed to pay the Government £3.3 billion to run trains until 2023, but the contract was ended prematurely after they failed to achieve revenue targets.
LNER will operate until a public-private partnership takes responsibility for both trains and track operations in 2020.
All VTEC staff have been transferred to LNER as part of the transition.
Managing director David Horne said: "Our immediate priority is ensuring a smooth transition for customers, staff and the communities we serve.
"Our message to everyone who depends on this service is that it is business as usual.
"Existing tickets are still valid on our services, and new tickets can be bought in the same way. The same scheduled trains are also in operation."
The East Coast route connects London King's Cross to stations in the North and Scotland including York, Leeds, Newcastle, Edinburgh, Aberdeen and Inverness.
Thank you to all our customers who have travelled with us on Virgin Trains East Coast over the past three years and best wishes to our fantastic staff as they continue our journey of improvement with @LNER
-- Stagecoach Group (@stagecoachgroup) June 23, 2018
Transport Secretary Chris Grayling refuted accusations from Labour and trade unions that his decision to end VTEC's franchise early was a "bailout" worth £2 billion.
"Stagecoach will be held to all of its contractual obligations in full," the minister said.
The switch from VTEC to LNER is costing an estimated £8 million, which includes marketing, rebranding and IT set up.
VTEC is the third private operator to fail to complete the full length of a contract to run East Coast services.
GNER was stripped of the route in 2007 after its parent company suffered financial difficulties, while National Express withdrew in 2009.
Trains were run by the DfT for six years up to VTEC taking over.