“That would be sufficient, since this expresses clear sincerity in the agreement,” explained Rabbi Dayan. “Alternatively, the investor and recipient can make a kinyan sudar that the investment will now be in accordance with the rules of heter iska. Some recommend doing both, drafting a heter iska and making a kinyan.” (Dagul M’revava Y.D. 177:19; Bris Yehuda 35:5[19])
“Does this work retroactively?” asked Ezra. “What about the two months that passed?”
“Restructuring the loan as an iska agreement only affects it for the future,” concluded Rabbi Dayan, “but it does not allow taking ribbis for the previous time.” (Bris Yehuda 40:23)
“Do you have a copy of a heter iska?” asked Ezra.
“I’ll be happy to e-mail you one,” said Rabbi Dayan. “Just give me your address.”
Ezra gave Rabbi Dayan his e-mail address. “Thank you,” he said. “I’ll be sure to take care of it promptly.”