It's actually quite easy to figure sales tax for an out of state sale where the state requires the seller to remit sales tax. Every state has a website where the seller can go to punch in the zip code and the percentage comes up automatically. Works fine for small businesses that have time to track every order. I don't know how the larger ones do it. Must be an app thing. I'm still into writing up invoices and scanning them to email back to the customer. So not a big deal here. Plus there are just so many states that have jumped on this wagon.

If a business has stores in your State say Bass Pro or a business has done a certain amount of sales to a State they are required to collect tax, small business Mom and Pops can get away with it if they don't do a large amount of sales.

So any city or county sales tax doesn't apply to remote sellers?

Yes it does. Punching in the zip code will determine the percentage of the sale.

True . . . . UNLESS they've done a show in that state and had to register their tax ID with that state. Then they're "supposed to" collect and send taxes for all sales, not just the show where bigger bucks are earned.

As this issue snowballs with more states jumping in here (you can see how many jumped on just this year from my first post) the Feds will eventually step in and make a one size fits all. My opinion anyway.

Now Wisconsin has a whole different approach. Out of state retailers are not yet required to remit sales tax collected from WI residents (unless they have a brick/mortar inside WI). Instead, WI residents are required to remit sales tax to the WI Dept of Revenue based on property the WI resident purchased outside Wisconsin and brought into the state without having paid sales tax on it.

https://www.revenue.wi.gov/Pages/FAQS/pcs-diff.aspx

Idaho's law is the same. Idaho residents are required to pay Idaho sales tax (6 %) on all out of state purchases. It is called a "use tax". There is a line for it on the state tax form.

Very few people do that and the state does not audit returns for that item, as a general rule.

Same here in NC. There is a USE Tax line item on the state income tax. You can calculate the actual if you track your purchases or there is a formula based on your adjusted gross income. I just use the formula as I do not keep track. For the amount I have to pay, it is not worth the trouble of tracking purchases.

But hearing most folks talking about out of state purchases, I get the feeling that most folks do not pay the USE Tax.

Give the states time and they will figure out how much revenue they are losing and start going after folks. Would be easy enough to use credit card records to establish the tax liability.

Chances are he does not have a MO state license to collect MO state sales tax.