Yes, every adult should file a federal and state tax return every year. The reason for this is to start the statute of limitations running. The IRS has a three-year statute of limitations for auditing a tax return that only starts if the tax return is filed. Your friends tax return would be very simple and some tax preparers will prepare it at a minimal charge.
I hope this helps!
If you do not like this answer or disagree, please look at one of the other answers provided. It is not necessary for you to try prove this answer is "wrong" or something with which you do not agree. This is a free service for you based on limited facts. Nevertheless, many times you need to consult an attorney with the details to get actual advice specific to your concerns. Do not put too many details in your questions or comments because this makes the information public and could hurt you. Government Regulations contained in IRS Circular 230 regulate written communications about Federal tax matters, including e-mail, between us and our clients. This is another attempt by the government to limit your rights and to extend the control of government over individuals and businesses. Nevertheless, such communications are either opinions or other written communications. This is not an opinion. It is other written communication and was not written to be relied upon, by itself, to avoid any tax penalties. In order to receive assurances of protection from tax penalties from a written communication, you should get an opinion letter. If you would like to discuss an opinion letter relating to any matter, please contact me and I will explain what is involved and what it will cost.
Many people are of the opinion that if they did not earn income then they do not need to file a tax return for that year. I believe this is erroneous. I advise you to file the tax return and simply state no income.