A number of operator's licences were used by the company to operate services, however in April 2013 all services were consolidated under the Red & White Services licence. The previous licences were as follows (the names of which generally come from companies which have been acquired in the past):
In January 1991 Western Travel purchased the eastern division of National Welsh Omnibus Services with 180 buses and depots in Brynmawr, Chepstow, Crosskeys, Cwmbran and Ross on Wye. The operation was renamed Red & White, the area's services having traded as Red & White Services until 1978. In 1992 Western Travel purchased Cynon Valley Transport which operated services in the Aberdare and Merthyr Tydfil areas was purchased with 46 buses.
In February 1992 a 10% shareholding in Rhondda Buses was purchased. Following the December 1991 collapse of National Welsh Omnibus Services, Rhondda Buses was formed to purchase the Caerphilly and Porth depots from the administrators. Rhondda Buses was owned by a consortium of British Bus, Potteries Motor Traction, Stevensons of Uttoxeter and Julian Peddle. In order to quell competition from neighbouring Red & White, Western Travel were sold a 10% share. Services were operated under the Rhondda fleetname from the Porth depot and Caerphilly Busways from the Caerphilly depot. Rhondda had expanded by purchasing the services of Parfitts Motor Services of Rhymney Bridge, who operated in the Merthyr Tydfil (competing with Stagecoach Red & White) and upper Rhymney valley area.
In December 1997 Stagecoach bought out the other Rhondda Buses consortium members which were now Arriva, FirstBus and Julian Peddle. Rhondda services were operated under the Stagecoach Rhondda fleetname, whilst the Caerphilly and Rhymney Valley services were incorporated into Stagecoach Red & White.
In February 2000 all operations were rebranded as Stagecoach in South Wales. The Ross on Wye based services were rebranded as Stagecoach in Wye & Dean and transferred to neighbouring Stagecoach West. In September 2000 the services of Phil Anslow Travel were purchased with 28 minibuses, giving Stagecoach a greater presence in the Eastern Valleys.
In November 2004 Stagecoach in South Wales purchased the remaining part of Phil Anslow Travel with six minibuses and 15 coaches. The bus services were integrated into Stagecoach in South Wales, whilst the coaching business became Red & White Coaches. Subsequently Red & White Coaches failed to remain profitable and ceased in April 2006.
In February 2006 Stagecoach purchased Eastern Valleys independent operator Crosskeys Coach Hire who traded as Glyn Williams Travel. Glyn Williams' operating area was within that of Stagecoach in South Wales and many of their trunk services had been operated jointly with Stagecoach.
As at April 2014, the fleet consisted of 367 buses and coaches. The fleet once consisted of step-entranced Dennis Darts, Volvo B10Ms and Volvo Olympians but now over time it consists mainly of Dennis Darts SLFs, Enviro 200s, Enviro 300s and Optare Solos. Unlike most Stagecoach companies, Stagecoach South Wales do not operate Double Deckers.
Stagecoach in South Wales began operating their first Gold standard vehicles on Saturday 28th November 2015. They are allocated to service X24 between Newport, Cwmbran, Pontypool and Blaenavon.
In April 2014 Stagecoach announced the intended closure of the Brynmawr depot along with a reduction of services. The depot closed on 21 July 2014 and became an outstation of the divisions Head Office.