Loan from a Corporation to another Corporation


Mr. X owns 100% shares of Opco. Mr. X and his family members own shares of Holdco. Holdo does not hold shares of Opco. There is excess funds in Opco and Mr. X does not need the funds for personal expenses. The only sensible way would fro Opco to loan funds to Holdo, any other suggestions or thoughts? Would we have to use the prescribed rate of 3%?