Hi ,
Yes this approach is supported in D365 F&O. Since every legal entity has its own COA you are simply adding more matching codes without changing its existing structure so there is no risk at all.
Best practices which should be followed for transferring the historical balances and detailed transaction history from the Old Accounts to the new Accounts are as mentioned below : -
1. We should keep at least 3-5 years of audit transaction details as it is depending on your audit requirements. Do not repost or try to delete as it may spoil your audit data completely and it would be difficult for you to explain this to audit team.
2.Transfer simply the balance amount not the exact transaction detail through a single journal entry from old account to new account on a cutover date as per your requirements. Also this should be done on a start of new fiscal period if possible thereby ensuring trial balances are kept in a good comparing condition.
3.Create a small customization by getting a custom field called “Is Suspended” flag on the Main accounts. Don't delete the old accounts simply enable this flag and then for whichever accounts you want you can enable this flag (Checkbox or toggle) so that if required you can generate a custom report from the accounts where this flag is enabled.
4. As mentioned in the second point try not to do this activity in middle of the year/fiscal period or at end of it to avoid unnecessary reconciliation activities.
Please try to follow these points and observe if it helps.
