Change in name of CA firm

Hi All, My friend is A Chartered Accountant in practice as a Proprietor since last 3 years and he is having a trade name registered with ICAI. Recently I had joined him as a partner without changing the trade name registered with ICAI. My question is if we want to change the trade name now then whether our existing firm with old FRN will get continued or we will get new firm name with new FRN?? Whether my partners proprietorship experience of 3 years will get continued in new firm?? Whether the Experience will count for bank audit empanelment under Partnership Firm?? Kindly suggest me whether I should change my firm name or not?