Pat,
Is your system pretty similar to Canada? They have two taxes in each sale, one a GST.
In the USA we have to acquire a 'resale' vendors license to be legal. This license gives you the 'right' to collect sales tax on goods you sell, then you must pay that tax back to your state. For me it's semi-annual, but for huge companies it's monthly and possibly even bi-weekly. For instance, in my county I have to collect 6% sales tax on what I sell. Every county has different amounts from 5% to 8 1/2% I think. Some states really rock people. some don't have sales tax. It's all done by state, then by county. If I sell to other counties in my state ( OHIO) I have to charge that counties sales tax. This just started a couple years ago. Very confusing and a PIA. If I sell out of state I don't need to collect Ohio sales tax but I'm supposed to collect the tax where ever I sell and voluntarily pay it, unless I'm handed a 'one-time sales' tax packet. This is sometimes done at shows such as the Wash. DC Potomac show.
You also need a business license which is a number used for your FEDERAL USA INCOME TAX and also used for many things if you have employees ( which I don't. My dogs don't count!

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Most manufacturers of ANYTHING in the USA give you a wholesale price on goods which you aren't required to pay sales tax on because you are the manufacturer of goods. For instance, if I buy clay I get a wholesale price and pay no sales tax. But when I make something and sell it I collect sales tax and pay to state. The state makes out because they get more tax from a FINISHED product than the raw materials.
Your annual FEDERAL TAX ( yccch!) is computed on how much you gross after all your INS and OUTS.
We also pay tax on items like gas and electric, water, etc.
Soooo, I hope you can better understand my comments about having a legal business vs. competing with the guy who makes some pots at the community center then wants to sell them at a convention or eBay.
In some far distance future when Dale is "King", vendors , ALL VENDORS, at conventions will be required to have a legal business license for THEIR BONSAI BUSINESS or they won't be allowed to vend. I don't see a problem with sales people being required to be legal. If I go buy a car, whether at a dealer or a private person, I have to pay tax and it gets paid. Thats true of just about anyones business. I think even eBay will be having problems soon. The US treasury and state treasurys are missing out....a lot!
Only one time was I at an Ohio show and saw a tax person walking around picking up business cards. There coulda been trouble there if they wanted too. So often now I'd kinda LIKE to see a tax agent walking around picking up cards and question a few sellers!
When we did the Puerto Rico BCI show two years ago they had THREE agents in the vendor room every minute and THEY totaled all sales each day and collected the taxes at the end of the show. It was all run through Pedro Morales' business. Lots of hassle for him but not too much for us vendors. I wonder how they'll be handling it at this years WORLD SHOW at the same site.
Dale