Major cities have an abundance of taxis. Charges are NT$70 for the first 1.5km and NT$5 for each additional 300 meters. An additional NT$5 is charged for every two minutes of waiting, and a 20% surcharge is added to fares between 11 p.m. and 6 a.m., NT$10 dollars tip needed for cab dispatched by phone and for luggage placed in taxi trunk. Charges may be raised during Chinese New Year holidays. Basically, taxi fares in all major cities are set by local city government itself and are in a minor discrepancy. Out-of-town or long-distance travels may not apply to meter charge; travelers are suggested to confirm charging method before getting on taxi.
50% additional to meter charge needed for cab travel to Taiwan Taoyuan International Airport. It costs around

NT$1,200 to travel from Taiwan Taoyuan International Airport to Taipei city, and NT$300 for traveling between Kaohsiung city and Hsiaokang airport. Island wide travel service available in fixed fares upon passengers needs.
Most drivers do not speak English, so it is a good idea to have hotel personnel write both your destination and your hotel's name and address in Chinese, along with the projected cost of each one-way trip. Any unreasonable charges or misdeeds from taxi drivers, please note down driver's name and license's plate along with time, place & happenings for further pleading to local supervision or foreign affair police department.

English Taxi Association: (02) 2799-7997
Taipei Foreign Affairs Police Station: (02) 2381-7475; 2381-8341; 23817494
Complaint about Taiwan Taoyuan International Airport taxi: (03) 398-2241; (03) 398-2177
Taichung Foreign Affairs Police Station: (04) 2222-3725
Kaohsiung Foreign Affairs Police Station: (07) 215-4342