You can shop tax-free at this store.
I bought souvenirs within the duty-free allowance.
This product will become tax-free starting next year.
At duty-free shops, you can purchase goods tax-free.
無税 is a general everyday term meaning no tax applies, whereas 非課税 is the more formal/legal term used for income, services, or goods that are explicitly classified as tax-exempt.
課税 means to levy or impose a tax, the direct opposite of 無税, which means no tax is charged at all.
duty-free goods
Compound of 無 (mu, 'without') and 税 (zei, 'tax').