It's impossible to say for sure without a lot more information, but this may explain it:
In order to claim a
deduction for unreimbursed business expenses, you would
have to itemize your deductions.
Additionally, the deduction is allowed only for the amount that is more than 2%
of your Adjusted Gross Income (AGI).
It is very difficult
to qualify for this deduction. That's because the expense limit is so high. In
order to qualify, your job-related expenses must be more than 2% of your AGI
(adjusted gross income).
Example: If your AGI
is $40,000, your expenses would have to be more than $800 ($40,000 x 2%). Even
then, you could only deduct the amount over $800. So, if your job-related
expenses were $1,000 you could only deduct $200 ($1,000 - $800).