Foreign citizens visiting Taiwan can take advantage of a sales-tax (VAT) refund system if they spend more than NTD3,000 in a single day at any participating shop no more than 30 days before departing from the ROC.
They’re required, of course, to take the items with them when they leave. Participating businesses (this official English-language list is likely incomplete, as it shows none in the eastern part of the island) includes almost every department store in Taiwan, some computer shops and several opticians. One recent amendment to the system provides that, if the total VAT refund amount is under NT$1,000 (which would be the case if the tourist has spent no more than NT$20,000) he or she may apply directly to the store for an on-the-spot refund.
Visitors who want to apply for refunds when leaving the country can do so at either terminal in Taiwan Taoyuan International Airport; at Kaohsiung, Taichung or Hualien airports; or (if they're departing by cruise ship or ferry) in the passenger terminals at Keelung, Hualien or Taichung harbours. At present there's no refund counter in Kinmen County; the Matsu Islands; or Tainan Airport, which has flights to/from Wuhan and Hong Kong in China, plus - starting late October - to/from Osaka in Japan.
The photo above is public domain, via Wikipedia.