While most Imperial member worlds will have a representative noble (a baron or a marquis) for those worlds whose populations embrase their Imperial membership there is a lot of mundane interaction. Far more than can be handled by just one noble. And while the Imperial Navy and the IISS have bases to handle their own business it is common practice for the representative noble to create a "High Commission" to handle civilian administrative functions. These can include:

• Provide aid and assistance for offworld visitors when dealing with locals. This could cover both legal and medical issues, as well as introducing offworld business men to the local trade and commerce organisations (if such exist).
  
  
• Provide information and advice to locals on dealing with other member worlds. (Both migration assistance for individuals, and to help local businesses deal with the implications of interstellar commerce.)
  
  
• Gather routine intelligence for various Imperial offices. This would involve both monitoring local media broadcasts/publications, and forming relationships with local dignitaries.
  
  
• Provide local resources for various Imperial offices. (For example, if a JSB investigation team were to visit, the local High Commission office could arrange hotels, transport, various accesses, etc, in advance so the JSB team could focus its attention purely on its investigation.)
  
  
• Serve as a recruiting office for the IN, IISS, etc.

On worlds with very low intersteller interaction the local SPA can be co-opted to provide these services but for worlds with an average or better degree of interstellar interaction there is a need for one or more High Commision offices.

Although like foreign embassies (with the representative noble as ambassadore), High Commission offices have no XT status. On the other hand using this generic organisation means dozens of Imperial offices can have input to all member worlds without having to set up their own parallel hierarchies, and the presence of a High Commission office in a prominent location serves to remind everyone they are members of the Imperium.

The following tables define the number of High Commission offices that could typically be found on an Imperial mainworld. They use the world's social outlook (as defined in the World Builders Handbook) and the world's starport as indicative of the degree of interstellar interaction.

Key:
- = No offices
spa = Office functions provided by SPA (where present)
1 = One office (usually in the planetary capitol)
primary = All primary cities have an office
secondary = All primary and secondary cities have an office
tertiary = All primary, secondary, and tertiary cities have an office.

How big is an office? Some will be small, perhaps a high street shop with a few assistants plus several back office staff. Others will be a more sizeable operation.

Office staff = host city pop code multiplied by 10, plus 2d6-2

Auxiliary services (cleaners, drivers, cooks, couriers, etc) are sometimes provided by hired locals (under supervision) as needed:

Example: Regina/Regina has a class A starport and its population is categorised as "friendly". Therefore there will be an office of the High Commission at each primary and secondary city (58 in total). There are 5 primary cities with populations ranging from 50 million to 90 million ... so their offices would have 70 to 80 staff (each) plus a further 7 or 8 locals (each) in their employ. The 53 secondary cities have populations circa 5 million ... so their offices would have 60 to 70 staff (each) plus a further 6 or 7 locals (each). In other words approx 4200 staff and locals for a population of 725 million.