[Edited 01-08-2019] This answer applies to tax years prior to 2018. Starting in 2019 there are no miscellaneous itemized deductions.
You can deduct safe deposit box rent if you use the box to store taxable
income-producing stocks, bonds, or investment-related
papers and documents. You can't deduct the rent if you
use the box only for jewelry, other personal items, or tax-exempt
securities.
If it qualifies, you can deduct it and certain other expenses as miscellaneous itemized deductions on
Schedule A (Form 1040 or Form 1040NR). You can claim
the amount of expenses that is more than 2% of your adjusted
gross income. You figure your deduction on Schedule A by subtracting
2% of your adjusted gross income from the total amount of
these expenses. Your adjusted gross income is the amount on Form
1040, line 38, or Form 1040NR, line 37. See Publication
529 for more information, including a list of other miscellaneous itemized deductions you might be able to take.
