Hi @nithyashankar71
Currently they do need to have the same chart of Accounts. Please see this article for reference:
Working With Multiple Companies In Acumatica In a Single Tenant (calszone.com)
You could use Restriction groups to connect accounts on the chart of accounts to one or more companies. Technically Restriction groups are a work-around that could allow different COA in one tenant.
That being said, I don’t recommend using Restriction Groups to control the COA access. Using restriction groups to grant or hide access to account numbers by company creates lots of maintenance on the restriction groups and financial reporting every time new accounts are added. ~ Just because something is possible, does not mean we should try it! :-)
Laura