At SVB we have departments (CC) that do not have employees yet have Cross Charging for those cost from other departments (CC).  Our model is based on weighted by Grade Level (assigned to a role) for internal labor and headcount for external labor.  Those departments without Internal or External labor are not weighted. 

My questions - what is the best way to allocate those cost since we do not have labor weighting for those departments?

Your input is so appreciated!

Depends on the size of those non labor CCs and the materiality of expenses in them. If the $s are small I would recommend a simple peanut butter spread, if the $s are material, define an allocation methodology based on some other metric like number of SW licenses, # server boxes, or any other metric that is relevant to those CCs.