Platform four and 5 at Peterborough were built when the two fast lines were put in. Platform four started being used on the 25 June 1972 ready for when the new though lines opened on the 2nd May 1973.

Platform 4 at Peterborough station has kept its platform number. It now has a lift shared with platform 5. It has an extra bit of platform at the northern end. Both ends of the platform have lost there platform ramps and now have a fence with a gate.

Most of the Virgin East Coast down trains to Leeds and Scotland use platform four. Platform 4 can also used by both up and down Norwich Cambridge and Birmingham Nottingham and Liverpool trains. Most of these now use the new platforms 6 and 7. Freight and light engines also use platforms 4 both ways.

Platform Four is on the eastern edge of a island platform with Platform 5 is on the outer western edge. The buildings on this island platform are of the style of architecture prevalent in the 1960's and 1970's bland and and insipid. But clean and just about fit for there use.

Platforms 4 and 5 are linked to the main station by a long foot bridge over the two fast lines. This footbridge was made longer when the new lines went in. There is at long last a lift that opened in 2014

There is also the old Post office bridge that was out of bounds in BR days, but was then used for many years for push chairs and the yellow mobility truck that carried wheelchairs and old people over the tracks who could not use the stairs. Peterborough station had no lifts, right to up till 2014! The bridge is still in use. This old Post office bridge now can be used by any passengers at the north end of the station