Friend hasn't filed in eight year. Want to help. How? Short form...

[clbutenhoff]

must file past taxes. how.

[SweetieJean]

TT Online Free and efile is only for 2017 returns. Years 2014, 2015 and 2016 require purchasing TT Desktop software for each year, and filing by mail. 

The least expense way is to pull each year's forms and instructions from the IRS and State tax websites, and do them by hand. However, there is a Statute of Limitations for a Federal refund of 3 years. Some states are longer. 

[fanfare]

does your friend have eight years of W-2s sitting in a drawer? see IRS pub 501 for who must file based on income and circumstances.