We build an accurate database of 5200 HCN and HNC rotation-vibration energy levels, determined from existing laboratory data. 20000 energy levels in the Harris et al., 2002ApJ...578..657H (HPT), linelist are assigned approximate quantum numbers. These assignments, lab determined energy levels and HPT energy levels are incorporated in to a new energy level list. A new linelist is presented, in which frequencies are computed using the available lab determined energy levels, and the HPT ab initio energy levels otherwise.