Anyone who starts an application through this link is attributed to you at first touch and is never re-attributed to someone else. That is the whole deal — you do not have to remind anybody whose client it was.
Give the loan officer the property, the price and the closing date — the request lands on your buyer's file, stamped with your name, and the letter comes from them. Anyone holding a CLEAR letter can check its reference and expiry here, no account needed.