An InterCity 225 on the East Coast Main Line
The InterCity 225 is an electric high speed train in the United Kingdom, comprising a Class 91 electric locomotive, nine Mark 4 coaches and a Driving Van Trailer (DVT). The Class 91 locomotives were built by British Rail Engineering Limited's Crewe Works as a spin-off from the Advanced Passenger Train project, which was abandoned during the 1980s, whilst the coaches and DVT were constructed by Metro Cammell in Birmingham and Breda (under sub-contract) in Italy, again borrowing heavily from the Advanced Passenger Train. The trains were designed to operate at up to 140 mph (225 km/h) in regular service, but are limited to 125 mph (200 km/h) principally due to a lack of cab signalling and the limitations of the current overhead line equipment. They are used on services from London King's Cross to Newark North Gate, Doncaster, Leeds, Bradford Forster Square, Skipton, York, Newcastle, Edinburgh Waverley and Glasgow Central.
They have also operated on the West Coast Main Line (WCML). In April 1992, one set a record of two hours, eight minutes between Manchester and London Euston, shaving 11 minutes off the 1966 record. In 1993 trials were operated to Liverpool and Manchester in connection with the InterCity 250 project.
In 1996, as part of the privatisation of British Rail, all InterCity 225s were sold to Eversholt Rail Group. Since then, the trains have been leased to all operators of the InterCity East Coast franchise, which is presently operated by London North Eastern Railway.
The InterCity 225 has a top service speed of 140 mph (225 km/h); during a test run in 1989 on Stoke Bank between Peterborough and Grantham an InterCity 225 reached 162 mph (260.7 km/h). However, except on High Speed 1, which is equipped with cab signalling, British signalling does not allow trains to exceed 125 mph (201 km/h) in regular service, due to the impracticality of correctly observing lineside signals at high speed.
Between 2003 and 2005, HSBC Rail funded with support from GNER, Bombardier Transportation, Alstom and others a complete rebuilding and refurbishment programme for both the Class 91 and Mark 4 coaches, called Project Mallard.
In June 2018, London North Eastern Railway (LNER) inherited all 31 InterCity 225 sets from previous operator, Virgin Trains East Coast (VTEC), as part of the franchise. As this point, LNER had intentions to begin replacing their sets with Class 800 and Class 801 trains from the Hitachi A-train family, which are branded as Azuma's. The first Azuma entered service with LNER on 15 May 2019, allowing for the first withdrawal of an InterCity 225 set. The withdrawals have gradually continued as more of the new Azuma trains have entered service and at the beginning of 2020, it was said that the final InterCity 225 sets will leave LNER's fleet by June 2020. However, LNER confirmed via their Twitter on 29 January 2020 that a number of sets will remain in service with them to benefit their December 2021 timetable change.
It was originally envisaged that all InterCity 225 sets would be withdrawn after their final operations with LNER, but operators are said to be taking some of the sets in. New operator Great North Western Railway will use InterCity 225s on its London Euston to Blackpool North services with Class 90 locomotives.  Twelve Mark 4 coaches are to be leased by Transport For Wales to replace its Mark 3 coaches on its Premier Service. Another new operator, Grand Union, is also proposing to operate InterCity 225s on its London Paddington to Cardiff Central services from December 2020.
During their operation with VTEC in 2016, there were plans to retain six to eight sets with shorter rakes for a new London to Edinburgh service, even with the Azuma takeover. However, having succeeded VTEC, LNER went ahead to introduce the new Azuma trains with no more plans in retaining any of the InterCity 225 sets due to high maintenance costs on the fleet. This was the idea until LNER announced they were to retain a number of their sets after all, but an amount of sets due to be retained by them has yet to be confirmed.
The formation of the InterCity 225 sets is below:- 
The total numbers of seats are 406 Standard and 129 First, giving the train an overall capacity of 535 seats.
One of the first models of the IC225 in the UK was by Hornby Railways, after previously releasing a 00 Gauge BR Class 91 locomotive in 1988. In 1990 Hornby Railways launched its first 00 Gauge models of BR MK4 rolling coach stock. Consisting of a BR Mk4 Driving Van Trailer (DVT), and three BR MK4 coaches, Tourist Open Coach (TSO), First Open Coach (FO), and a Catering Service Car (RFM).  Hornby Railways launched its first full model version containing a BR Class 91 locomotive, along with a BR MK4 Driving Van Trailer (DVT), and two MK4 Tourist Open Coaches as a complete train set in 1991.
VTEC InterCity 225 arrives into London Kings Cross.
First Class interior on a VTEC InterCity 225 set.