Escrow is NOT a legal requirement. Escrow does however, very easily help you to meet a legal requirement and still help to keep you safe. Upon filing the I-526, Visa Petition, YOU have to PROVE that you have "committed" your capital to the business or "project" that serves a the basis for your visa petition. You could simply hand the money over to the project developer or to a Regional Center directly with no strings attached. However, if your I-526 is denied then it's too bad, so sad about the money that has been sunk into a particular project. Escrow is generally used to 1.) DEMONSTRATE THAT THE MONEY IS COMMITTED, "If the I-526 is approved then the money is irrevocably handed over to the project principal/developer." and 2.) PROTECT YOU BY HAVING A REFUND CLAUSE "If the I-526 is denied, then the money is returned". In either scenario, the FULL amount of capital must be "committed" upon filing the I-526. For your own peace of mind (or is it piece of mind?), stay away from "promissory notes", 95 to 99% will be found unacceptable by USCIS.
An EB5 investor must be “invested” or “in the process of investing” into the New Commercial Enterprise. Escrow accounts are commonly used by New Commercial Enterprises for EB5 investments, and commonly receive the entire amount of the investment at one time. However, the particulars of the escrow and transfer of funds will be a matter of discussion for you and the New Commercial Enterprise. Of course, retaining an experienced EB5 attorney, like the attorneys at our law firm, can help you with reaching your U.S. Immigration goals.
I am assuming you are investing in your own EB-5 business and the legal requirement is that you as the investor has invested or are in the process of investing. By having placed the entire required amount of personal funds into escrow you may direct the investment funds into the New Commercial Enterprise by installments according to a comprehensive business plan.