Whether you sell items only online or not, the IRS and most states consider any income you earn from these sales to be taxable. Whether you will owe taxes or not. Whether or not you owe taxes for the sale of personal items, goods or services online will depend on several factors, such as whether you made a profit. Generally, there is no need to report online sales of used personal items.
Selling your old bike on Craigslist is an example of this type of sales. Losses on personal goods are not deductible on online retailers' tax returns. The general rule is that if you used the items and then sold them for less than you bought them, then you don't have to pay sales tax. However, if you were to sell an antique or collector's item that has appreciated since you first purchased it, you'll likely have to pay taxes on profits.