The answer to the original question is BOTH.
The two regions / companies which used Pullmans mostly were the Southern (SR) and the Eastern (LNER) , the LNER use them in all Pullman trains on the East Coast Mainline, but also on the Great Eastern section too. From Kings Cross the Queen of Scots ran to Edinburgh, detaching cars at Leeds, and also a Yorkshire Pullman, which divided at Doncaster part going to Hull and part to Bradford. In BR days there was a Tees Tyne Pullman too, The Master Cutler which ran from Marylebone to Sheffield was later diverted to start from Kings Cross.
From Liverpool Street before World War 2 the Clacton Belle catered for holiday makers. The Hook Continental was a boat train which included Pullman cars mixed in with ordinary coaches. This all stopped on the outbreak of War, never to return.
The Southern was a big user of Pullmans. There was a Pullman train from Victoria to Margate and Ramsgate called variously the Thanet Belle and Kentish Belle . The famous Golden Arrow served Channel Ferry traffic, Victoria to Folkestone and / or Dover, this started as an all Pullman train, but in its last days it became a mixture of ordinary carriages and Pullmans. During the day various boat trains ran between Victoria and the Channel Ports which included one or two Pullmans in a train otherwise composed of ordinary carriages. This lasted until electrification. Similar trains connected London to Newhaven. Before the War the Hastings expresses contained a Pullman car used as a dining car.
The London to Brighton route had many Pullman trains, and even after electrification trains which included a Pullman car operated regularly right down until the 1960s. Special electric sets were provided which contained a unique composite Pullman car. The all Pullman Southern Belle, which became the Brighton Belle just after electrification, provided luxury travel to Brighton from London, until 1972.
To the South and West from Waterloo there were plenty of Pullman trains. The Bournemouth Belle was an all Pullman train, which lasted until 1967. The Devon Belle which included observation cars was also all Pullman but was not so long lived and stopped running in 1954. Trains to connect with Trans Atlantic liners at Southampton were usually all Pullman, but may also have been mixed Pullman and ordinary stock. Some of these carried names like "The Cunader".
Race meetings brought out the Pullmans too. Epsom Derby saw Pullman trains being run for both Punters and for Royalty to Tattenham Corner where the station was extended to handle large crowds on race days. The air shows at Farnborough also attracted Pullman specials and Portsmouth was a destination when the Navy held special events there.
Other railways flirted with Pullmans from time to time. The LMSR was not much in favour although the Caledonian section used some Pullman cars and had an observation car on the Oban line. The cars were bought by the LMSR in 1933 who then used them as normal stock.
The GWR used Pullmans in the 1920s but decided to introduce luxury carriages of its own before the 1930s. Pullmans returned in 1955 with a South Wales Pullman from Paddington to Swansea, which was replaced in 1960 by the diesel Blue Pullmans.
The Metropolitan Railway included a Pullman car in certain trains between Aylesbury and Moorgate aimed at the City businessmen. It stopped in 1940 and never resumed. Metropolitan railway stock was normally compartment carriages so the Pullman car was quite a contrast.
Pullman cars were used for Royal trains when an overnight stop was not required, and also for foreign dignitaries from Channel ports visiting Britain.
This copied from the web is one of the EMUs which included a Pullman car.
