If goods are purchased by an individual for the purpose of resale and then consumed or used instead of being sold to a retail consumer then use tax would be due on those goods. Additionally, in many jurisdictions, if those goods are held in inventory and not sold by the end of the year, use tax would be paid in lieu of the sales tax that would have been collected if they were sold.

Resale Certificates Explained: What New Business Owners in the US Need to Know
Resale certificates are essential tools for new businesses to purchase inventory tax-free. By preventing double taxation, they ensure retailers only collect sales tax from end

