Service 143 was introduced by Midland Red Omnibus Company Limited (MROC) on Saturday 13th January 1979 as part of the new “SevernLink” MAP area scheme. The service was a short-working variation of Service 144 running over the same route between Birmingham and Marlbrook, then via Catshill and Sidemoor to terminate to Bromsgrove. The service then continued to the Charford area of Bromsgrove where it terminated.
Midland Red Omnibus Company Limited (MROC) ceased trading as a bus and coach operator at the end of services on Saturday 5th September 1981. The operations of Bromsgrove depot, and with it the operation of Service 143, passed to the newly formed Midland Red (West) Limited from the following day.