By the mid-1930s, the BMMO network was expanding rapidly and the company were starting to run out of available service numbers. To free up numbers for new services, local area networks were renumbered with a prefix letter to represent the area when the network operated, so thus on Monday 7th January 1935 all local Malvern area services were renumbered in the range M10–M30 (with service number M13 being omitted for some reason. Unlucky?).
With the renumbering of local Malvern area services on Monday 7th January 1935, Service 370 running from Malvern Link to British Camp via Belmont, Great Malvern and Malvern Wells, became Service M10 for the full route and Service M20 for short-workings.
The route had first been established by Birmingham and Midland Motor Omnibus Company Limited (BMMO—Midland “Red†Motor Services) for the 1922 summer season, but as all local Malvern services ran as Service 48, it was known simply as the “British Camp†service. Operation was Monday to Saturday during the summer seasons, and an application for a licence to operate on Sundays made for the 1924 season met with resistance from Councillors, who did not want to promote Sunday trading.
From Saturday 16th May 1925, BMMO gave individual numbers to the local Malvern routes, and at this time the “British Camp†service became Service 274, and operation of the 1925 summer season started two days later on Monday 18th May 1925. The licence to operate on Sundays had been granted for the 1925 season on the grounds that buses would not wait more than 3-minutes at Belle Vue Terrace, and at the close of the season the service continued in operation on Sundays only throughout the winter.
Service 274 was renumbered to Service 370 for the 1928 season as part of the reorganisation of all BMMO services on Saturday 11th February 1928.
The route initially ran from Great Malvern (Belle Vue Terrace) direct to British Camp via Malvern Wells, but most journeys were extended to Malvern Link for the 1925 season. By the time it became Service M10 it had also been rerouted to include Belmont. Short workings of Service M10, between Great Malvern, Malvern Wells and British Camp, were operated as Service M20.
By the 1936 season, operation of Service M10 was reduced to just one weekday journey each day. Service M11 and Service M21, both running via Wych Cutting, took the majority of the traffic for British Camp.
Within days of the outbreak of the Second World War, the government announced the introduction of fuel rationing and the 1939 summer season was cut short. All summer season services were suspended on Saturday 23rd September 1939. Service M10 made a brief return for the 1940 season, starting on Saturday 1st June 1940, but vehicle shortages saw it suspended again just four days later. Full operation of Service M10 and Service M20 resumed again from Saturday 13th July 1940.
The 1940 summer season came to a close at the end of September, and at this time Service M10 was withdrawn.
| M | 1 | 0 |
| July | 1938 | Malvern Link ↔ Malvern Wells ↔ British Camp |