I am a small, but long-time eBay seller, and I am licensed to collect sales tax in my state. I know how to fill out eBay's sales tax table (Account > Site Preferences > Payment from Buyers > Use Sales Tax Tables) and correctly apply sales tax to the sale, shipping, other services based on the rules of my state.
This morning I had a sale which showed a Sales Tax Rate for an amount less than my state-assigned rate. I did not change my tax table and my state did not change the rate for my locality. I checked my sales tax table and found the correct amount in the sales tax table. Further, the rate shown on the buyer's invoice changed (to another incorrect amount) while I was preparing to send the invoice to the buyer and investigating this discrepancy.
This is screwy. eBay should not be changing tax rates without involving the seller. Watch your sales tax rates.
