Pretty sure receipts are not necessary unless audited.
Otherwise I have been prepared for this day by tracking every purchase and sale for the last 5 years. I keep every Paypal receipt, every shipping receipt, photos, every posting I sold or bought from, and every email exchange with the seller or buyer. All are filed as PDF’s and tracked in an excel spreadsheet so I can know how much I made or lost on each item. Typically lose thousands every year on the total amounts while some items may be "profitable", overall I am a loser! But prepared for an audit.
Some have questioned whether I actually have owned as many cables I have stated, and yes, I can prove every purchase and every sale.
Let’s see how much Friends and Family saves us from reporting. What is the 2024 number, $600 again?