Comment by clogston

IRS requires you to authenticate yourself via one of two mechanisms if you efile (regardless of who you do your taxes with):

1) Prior year AGI

2) Electronic filing PIN

They can also issue a taxpayer a special Identity Protection PIN. If you're issued one of these you MUST use it.

There are two groups of people that don't need to "authenticate" at all:

1) Anyone who didn't file the previous tax year

2) Anyone filing by mail