I PAY A LOT OF POSTAGE ON ITEMS I SELL ON EBAY

[DR ROSE]

I assume the 1099-K will be for the gross sale amount less EBAY's fees.

But what about the postage I pay????

Most of the items I sell are at low prices so usually the postage is more than my net profit....

Can't I deduct it as an expense even if it is a hobby.

To be considered a business do I have to register as a business and get ID etc???

[kdevere]

Beginning in 2018, the IRS doesn't allow you to deduct hobby expenses from hobby income. you must claim all hobby income and are not permitted to reduce that income by any expenses. For tax years prior to 2018, you can deduct hobby expenses as an itemized deduction subject to 2% of your adjusted gross income.  The taxpayer must still report the income they receive on Schedule 1, Form 1040, line 21.
If it is business/gig income, the postage would be a deductible expense on the Schedule C.