16 bits.

Taiwan credit card numbers are generally 16 digits, such as Taiwan post office bank credit card, Taiwan visa credit card, etc. The credit card validity period is generally 3 years, and some bank credit cards are valid for 5 years.

Taiwan Province, referred to as "Taiwan", is a provincial-level administrative region of the People's Republic of China, with the provincial capital Taipei. It is located on the continental shelf along the southeast coast of China, bordering the Pacific Ocean to the east and the Taiwan Strait to the west from Fujian Province. It faces the East China Sea to the north and the Bashi Strait to the south, opposite the Philippine Islands.