[1] The trains were built jointly by Hitachi, Kinki Sharyo, and JR Kyushu (Kokura factory).

[2] 811 series trains are used on "Local" (all-stations) and "Rapid" (limited-stop) services on the following lines.

[3] As of 1 October 2017[update], the fleet consists of 108 vehicles, formed as 27 four-car sets.

As of January 2013, P8 carries promotional vinyls for the Kyushu Heritage Museum, and the other two sets have been returned to the standard colour scheme.

Refurbishment changes include replacing the traction control equipment with SiC-VVVF equipment, changing to a single-arm pantograph, tinted passenger windows, full-colour LED destination indicators, and replacement of the former transverse seating with longitudinal bench seating.