If it is a defined space in your home used exclusively for business-related items, then it will qualify as a home office deduction .
If it is a storage unit at another location that you pay a monthly fee to lease, then it can be considered a miscellaneous business expense and deducted in the same manner as your other business expenses. If only a portion of the unit is used for your business items, you will need to pro-rate the cost accordingly.
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