2
For intercompany project transaction posting system is considering only ledger accounts defined for All in 'Ledger Posting setup'.

In case ledger account are not defined for All in 'Ledger posting setup', system is triggering posting error message at each stage
Lending company: Timesheet entry, Free text invoice (Intercompany invoice posting)
Borrowing company: Posting pending vendor invoice (Intercompany invoice)

this is by design currently
https://fix.lcs.dynamics.com/Issue/Details?bugId=569930&dbType=3&qc=f9daa23c0b43467deb2c7816bb2a0d6b4153964b2c74d7e155e79fb6572a2956
STATUS DETAILS
Inactive
Ideas Administrator

Thanks for submitting this issue but we will track and address on this related idea:

Microsoft Idea  · Cost posting for inter-company timesheets – All/All required (dynamics.com)

Andy Choi

PM, Project Management and Accounting

Microsoft