The prison is part of the North East Region and is run by Sodexo. It has a capacity of 1348 and the #1governor is Tony Simpson. Northumberland was formed from the merger of HMYOI Castington and HMP Acklington, completed in October 2011. From the 1 December 2013 HMP Northumberland formally transferred to the management of Sodexo Justice Services.
There are 15 house blocks with five holding vulnerable prisoners, including sex offenders. House blocks range from 40 to 240 beds and are of a variety of layouts and ages. There are two induction units (one for vulnerable prisoners), dedicated integrated drug treatment system (IDTS) units, drug recovery wing, drug-free wing, category D/low risk unit, and an older vulnerable prisoner unit.