The default company can be changed using command line arguments, affecting the ISA and GS sender ID segments.
Sender ID segments in Company Setup
To change the default company, a single argument is needed. "Setcompany" followed by the company ID of the company you wish to set.
"setcompany <ID>"
The Company's ID in this case is not its EDI identifier, but the value of the ID row in the COMPANY_SETUP table. It can also be found in the Company Setup window:
Company selection in Company Setup
Example
The command argument setcompany 3
will set the default company to ID = 3, which is HIPAASUITE2 in the example picture above. The log entry for this command will be
Excerpt from log. Default company changed.