London Buses route H12 is a Transport for London contracted bus route in London, England. Running between South Harrow and Stanmore, it is operated by Metroline.
Route H12 commenced operating on 14 November 1987 between South Harrow Station and Harrow Weald Masefield Avenue via Eastcote Lane - Rayners Lane - Alexandra Avenue - Rayners Lane Station - Village Way - Cannon Lane - Eastcote Road - Marsh Road - Bridge Street - Pinner Station - Elm Park Road - Uxbridge Road - Hatch End - Uxbridge Road - Long Elms - Harrow Weald Garage - Uxbridge Road - Masefield Avenue - Newbolt Road - Binyon Avenue - Bridge Road as a Monday to Saturday service. The route was initially operated by Harrow Buses from their North Wembley (NW) garage using MCW Metroriders. Route H12 is a renumbering of route 209.
On 20 August 1988, the route was withdrawn between Harrow Weald Bus Garage and Harrow Weald Masefield Avenue and was diverted to Stanmore Station via Uxbridge Road and Stanmore Broadway.
On 1 December 1990, the MCW Metroriders were replaced by Optare StarRiders.
On 12 October 1991, the allocation was transferred to Harrow Weald (HD) garage and the Optare StarRiders were replaced by Carlyle Dartline bodied Dennis Darts.
On 4 July 1992, two school day journeys were introduced using MCW Metrobuses.
On 15 September 1996, a Sunday service was introduced and the Carlyle Dartline bodied Dennis Darts were replaced by Plaxton Pointer bodied Dennis Darts.
On 4 September 1999, the route passed to Sovereigne operated from their Edgware (BT) garage and was converted to low floor operation using Plaxton Pointer 2 bodied Dennis Dart SLFs. At the same time, the School day journeys passed to London Traveller from their Harlesden (HN) garage using MCW Metrobuses.
On 3 November 2001, the allocation was transferred to Harrow (SO) garage.
On 1 November 2002, the school day journeys was included in the sale of Metropolitan Omnibus sold to Thorpes and was transferred to Wembley (FE) garage. The MCW Metrobuses were replaced by East Lancs bodied Volvo Citybuses at the same time.
On 4 September 2004, the route passed to Metroline operating from their Harrow Weald (HD) garage and was converted to double deck operation using Plaxton President bodied Volvo B7TLs. The School day journeys operated by Thorpes were withdrawn at the same time.
On 3 September 2011, the route was retained by Metroline.
In 2016, the Sunday allocation was converted to Wright Eclipse Gemini 3 bodied Volvo B5LH.
Route H12 operates via these primary locations:
- South Harrow Bus Station
- Rayners Lane Station
- Pinner Station
- Hatch End Station
- Headstone Lane
- Harrow Weald Bus Garage
- Stanmore Broadway
- Stanmore Station Forecourt