The answer is students are not required to sign an NLI
|

Although student-athletes aren't required to sign an
NLI, student-athletes and their families like the
security of signing an NLI in that they know where
the student-athlete is going college the next year,
but also all other colleges must stop recruiting the
student athlete once the NLI is signed.
The other answers are incorrect. The NLI can be
received by fax and once signed can be sent back to
the college or university by fax. It will be
considered valid.
Student-athletes make verbal commitments all the
time to college coaches, but if the circumstances at
that college change (i.e. the coach is fired or goes to
another school) the student-athlete may not want to
commit to that college any longer. While it
demonstrates great integrity to keep your word, a
student-athlete is not obligated to sign with the
school to which he or she verbally committed. Also
note that this works in reverse too. If a college
coach verbally commits to a student-athlete and a
better player at the same position becomes
available, the college coach isn't bound by his
verbal commitment either.
Finally, the NLI is not good for four years. It is a
contract for a student-athlete to attend a college or
university for one year in exchange for an athletic
scholarship for one year.
Source: National-Letter.org - Frequently Asked Questions