Transfer assets & liabilities between 2 companies

Hello, Narmada,

It seems existing companies will be abandoned, and new company created as a merged.

In such case, I have always done migration like regular opening balances migration: creating external customer invoices and external supplier invoices file from a database queries returning records in standard external file format, and then loaded them via external invoice functionality, 

In customer case, dedicated migration account was placed instead of invoice revenue posting and, and tax code substituted by NOTAX (and net amount = gross amount), if tax was already handled by source company or original kept if due in new one. 

In supplier invoice case - same approach for finally posted invoices, prelposted items migrated without posting lines added.

For fixed assets - object import functionality (by data migration job).

Cash accounts balances - manually through mixed payment with direct cash statements on dedicated account

Similarly, open customer and supplier payment items - either through external payment file or manual mixed payment (with opposite direct cash on dedicated account)

And finally - manual GL voucher (external voucher load) to transfer remaining GL positions (excluding ledger accounts - voucher balanced by dedicated accounts mentioned above).

I believe it is simplest way and relatively easy to perform - does not require complex data transformation. I have done it several times already and it took me up to 2 days (and number of invoices migrated each time was more that thousand).