A second account is not required, but you will probably prefer to open a second account on PeerStreet. If you hold investments from multiple platforms in a single account, then the SD IRA fees will be charged to your account. However, if you have multiple accounts, then each platform will likely pick up the fees, as stated in their respective SD IRA terms. Separate accounts also make it easier for PeerStreet to be named the interested party on the account you open with us and other platforms will not be able to see the investments you are making through PeerStreet.
