A Notice is served on you at your previous rented Address , that might the only available address to the other party to serve notice on you- The fact remains that Notice is served on you though not personally , you have received the Notice , You ae also admittign that Notice is recieved by You - it is better to reply to the said Notice !
actually your question is little be confusing. you don't specify that what type of notice you have received through ur friend. If it is relating to cheque bounce( NI Act) than u have opportunity to give reply that notice up to first hearing of concerned case but if it not NI act notice than my advice that u should reply as soon as possible.
Dear Artix, From plain reading you question that you have received notice.You have not stated that whether you informed you present adress.Hence according to me you have to reply the said notice without delay otherwise you have to face legal procedings.