Do I invoice and journal entry for intercompany transactions?

We have two separate companies that are owned by the same person and work under the same building, currently the Real Estate Management company is invoicing the airline company for Rent every month. How do i handle these intercompany transactions? Do i continue using the invoicing method and doing a month end journal entry to put the rent expense directly into the due to/from account? Or do i skip invoicing the rental expense account and hit the due to/due from account on the invoice? Please advise.