I used Intuit Turbo Tax Online, FREE if you have a simple tax return.
Each year I find those online services better than the last.
But when, after finishing on Turbo Tax, I went to submit my .tax file to Revenue Canada via NETFILE, I found I did not have my four-digit access number.
Instead I printed the PDF. And sent it by snail.
… your taxes filed?
Rick McCharles 
Great software, although I used to use the quick tax version. Also had the same problem as you and needed a 4 digit number. Snail Mail is still the best option!