this does not reflect the situation in the US, where krebby appears to be located. (i checked first.)
here's a little page from washington state on it, which matches my understanding of the situation in most other states: https://dor.wa.gov/get-form-or-publication/publications-subj...
> Have you ever made a retail purchase and the invoice didn’t include retail sales tax? This may occasionally occur, especially if you purchase items over the internet or from out-of-state vendors. ... However, the buyer has a responsibility to pay use tax to the Department of Revenue even if the seller doesn’t collect it.
> Also, an invoice should never have a single figure that “includes retail sales tax.” If you receive such an invoice, contact the vendor and ask for a new invoice with the retail sales tax separately stated. Washington law requires that customer sales slips, contracts, invoices or other sales documents separately state the amount of retail sales tax due.