Investors & landlords

this is from a Forbes article in 2018

https://www.forbes.com/sites/greatspeculations/2018/07/13/investment-fees-are-not-deductible-but-bor... 

The new law effective for 2018 -2025 disallows the deduction of "2%" miscellaneous itemized deductions including “expenses for the production or collection of income.” That list does not include short-selling expenses. Section 67(b) excludes certain deductions from the “2-percent floor on miscellaneous itemized deductions;” including (8) “any deduction allowable in connection with personal property used in a short sale.”

Brokers charge short sellers “stock borrow fees” or “loan premiums.” Tax research indicates these payments are “fees for the temporary use of property.” Some brokers refer to stock borrow fees as “interest expense”. Borrow fees are not interest expense, so investors should not include them in investment interest expense deductions on Schedule A.

current (2021) schedule A instructions state. (Note: These are contrary to what is in the Forbes article which concludes they're deductible as a misc deduction (that would be line 16 on current schedule A)

Only the expenses listed next can be deducted on line 16. For more information about each of these expenses, see Pub. 529.

(Pub 529 does not mention these fees. Neither does PUB 550 -Investment income/expenses) 

• Gambling losses but only to the extent of gambling winnings reported on Schedule 1 (Form 1040), line 8b.
• Casualty and theft losses of income-producing property from Form 4684, lines 32 and 38b, or Form 4797, line 18a.
• Federal estate tax on income in respect of a decedent.
• A deduction for amortizable bond premium 
• Deduction for repayment of amounts under a claim of right if over $3,000. 

• Iment-related work expenses of a disabled person.

here's what another current  source states: 

Although it’s uncertain in the tax code, there is a rationale for investors to deduct stock borrow fees as “other itemized deductions” on line 16 of Schedule A (itemized deductions). The code seems to include it, but Schedule A instructions do not. Consult a tax professional.

I will point out that the IRS instructions and Pubs may not be authoritative. there was a tax court case not those many years ago where taxpayers relied on an IRS publication. The problem was that the Pub did not conform to the tax law. thus the taxpayers lost and had to pay additional taxes, penalties and interest.    

this is IRC 263(h)

(h)Payments in lieu of dividends in connection with short sales
(1)In general
If—
(A)a taxpayer makes any payment with respect to any stock used by such taxpayer in a short sale and such payment is in lieu of a dividend payment on such stock, and
(B)the closing of such short sale occurs on or before the 45th day after the date of such short sale,
then no deduction shall be allowed for such payment. The basis of the stock used to close the short sale shall be increased by the amount not allowed as a deduction by reason of the preceding sentence.

note the code section does say where an investor can deduct them if they are deductible 

Thomson Reuters Checkpoint  Handbook states after the 45th day, they would be deductible on Schedule A line 16. Note that these are not mentioned in the Schedule A instructions above and their conclusion on where to deduct them is contrary to PUB 550

from pub 550

Payments in lieu of dividends. If you borrow stock to make a short sale, you may have to remit to the lender payments in lieu of the dividends distributed while you maintain your short position. You can deduct these payments only if you hold the short sale open at least 46 days (more than 1 year in the case of an extraordinary dividend, as defined later - see PUB 550) and you itemize your deductions.
You deduct these payments as investment interest on Schedule A (Form 1040). See Interest Expenses in chapter 3 od PUB 550 for more information.
If you close the short sale by the 45th day after the date of the short sale (1 year or less in the case of an extraordinary dividend), you can not deduct the payment in lieu of the dividend you make to the lender. Instead, you must increase the basis of the stock used to close the short sale by that amount.
To determine how long a short sale is kept open, do not include any period during which you hold, have an option to buy, or are under a contractual obligation to buy substantially identical stock or securities.
If your payment is made for a liquidating distribution or nontaxable stock distribution, or if you buy more shares equal to a stock distribution issued on the borrowed stock during your short position, you have a capital expense. You must add the payment to the cost of the stock sold short.
Exception. If you close the short sale within 45 days, the deduction for amounts you pay in lieu of dividends will be disallowed only to the extent the payments are more than the amount you receive as ordinary income from the lender of the stock for the use of collateral with the short sale. This exception does not apply to payments in place of extraordinary dividends

so in summary I don't think there is a definitive answer for investors as to whether or not the borrowing fees are deductible and if they are where on schedule A