Important: this could also be a question about any letter from the Respondents or their agents.
Yes, you should respond to anything you receive in the first 2 Rounds. After the 3rd Round, it is optional, because there is no more negotiating at that point. However, in some cases, we have assisted some people with a response after the 3rd Round, because they have received threatening letters, and we felt they should respond – but you don’t have to. Anything you get in the first 2 Rounds, you should respond to.