It is a short (usually 3-5 characters long) alpha-numeric (or combination of both) code and differentiates between different travel agency offices. The code is unique to each travel agency.
A PCC code is important to insert negotiated rates as these can be defined/ secured to an agency by using their code. Based on the location of the agency, travel providers can negotiate conditions and restrict or allocate certain privileges.
PCC allows travel agencies to stay anonymous and be identified only by their location. The code also allows the travel agency to see all booking of an individual agent. It is commonly used in the aviation industry.
Synonymous for PCC are Subscriber ID or Office ID (OID).