While an investor can choose which property to sell (exchange) and identify replacement properties, the investor/taxpayer may not control or have access to the funds in between those two events. For that reason, the use of a qualified intermediary is necessary.
Individuals, C corporations, S corporations, partnerships (general or limited), limited liability companies, trusts and any other taxpaying entity may set up an exchange of business or investment properties for business or investment properties under Section 1031.
A 1031 exchange does not obviate the need for a realtor. Quite to the contrary, in most cases an Exchanger has an even greater need for a realtor due to the time constraints placed on Exchangers.
A Qualified Intermediary, or QI, is an independent third party to the transaction whose function is to prepare the documents necessary to create the exchange, as well as to act as the independent escrow agent for the exchange funds.