I wrote a piece on the Fusion CPA blog about garage and yard sale income, because it comes up more than you would think, and the usual answer people have in their head is close but not quite right.
The short version: most of what you sell at a garage sale is your own used stuff, sold for less than you paid. That is a loss, and it is generally not taxable.
Two things change the answer.
You sold something for more than you paid. That profit is a capital gain and it is taxable. The classic case is an inherited piece or a collectible: a rare record bought for $10 and sold years later for $500 is a $490 gain, taxed the same way a stock sale would be. How long you held it decides whether it lands as long-term or short-term.
You are doing it repeatedly, for profit. This is the one that catches people. The IRS looks at pattern and intent rather than the size of any single sale. Three questions tend to separate a cleanout from a business:
Yes to those and you may be running a business in the eyes of the IRS, which means Schedule C, and potentially self-employment tax on top of ordinary income tax.
Third-party platforms like PayPal, eBay and Etsy have to issue a Form 1099-K once you cross $20,000 in payments and 200 transactions in a calendar year. Congress restored that threshold in 2025 after several years of a much lower figure being scheduled to take effect.
Two things worth being clear on, because they trip people in both directions:
A 1099-K is an information return. It reports that a platform moved money to you. Whether you owe anything still depends on whether you made a profit.
Some platforms issue one below the threshold anyway, so it is worth checking your own platform's policy rather than assuming.
The full article works through a composite example of someone who spends a year clearing out inherited furniture across two marketplaces, stays well under both thresholds, and owes nothing. Then the following year they start buying furniture specifically to refinish and resell, and the same activity moves into business territory even though no 1099-K ever shows up.
That shift is the thing to watch for. It is gradual, and it does not announce itself.
State rules add another layer, since treatment of casual sales and reseller income varies, and some states have their own permit or sales tax requirements once you cross from personal into business.
