Here are 2 ways to activate your VISA Debit Card for overseas usage:
1. Visit a Post Office:
    Please bring your national ID card, passbook, and authorized seal in person to any post office.
    A foreign national must present an Alien Resident Certificate (ARC); if no ARC, a passport and a  
    Record of ID No. in the Republic of China are required. For branch-limited account holders,
    please  visit your home branch.
    
2. Go to the Nearest Postal ATM or Log into WebATM:
    Select the on-screen option ATM CARD FOR OTHER SERVICES.
    Please Note:
    If there's no cardholder name on your card, activation at a Postal ATM is not applicable.  
    

To meet your spending needs, there are options available to increase your temporary purchase limits:
1. To increase the daily limit up to NT$150,000; the monthly limit up to NT$200,000:
    (1) Apply at a Branch:
          You need to provide your national ID card, passbook, and authorized seal in person to any
          post  office.
          A foreign national must present an Alien Resident Certificate (ARC); if no ARC, a passport and
          a  Record of ID No. in the Republic of China are required.
          For branch-limited account holders,  please visit your home branch.          
    (2) Contact Customer Service Center:
          Just call our 24-hour toll-free hotline: 0800-700-365 to speak with a customer service officer.  
          (from a mobile, please call: 04-23542030; from overseas, please call: +886-4-2354-2030.)
    (3) Log into WebATM:
          Please use your Postal VISA Debit Card and a card reader via WebATM  
          (https://webatm.post.gov.tw).  Select the option ATM CARD FOR OTHER PURPOSES.

2. To increase the daily limit up to NT$150,000; no monthly limit:
    Only applying in person is allowed. You need to provide your national ID card, passbook, and  
    authorized seal in person to any post office. A foreign national must present an Alien Resident
    Certificate (ARC); if no ARC, a passport and a Record of ID No. in the Republic of China are
    required.  For branch-limited account holders, please visit your home branch.

Please note:
After limit increase, the maximum purchase limit per transaction still remains NT$60,000.
Temporary limit increase will be valid for 30 days from the application date.

You can temporarily increase your overseas withdrawal limits in the following ways:
1. To increase the daily limit up to NT$100,000; the monthly limit up to NT$300,000:
    (1) Apply at a Post Office:
          You need to provide your national ID card, passbook, and authorized seal in person to any
          post office.
          A foreign national must present an Alien Resident Certificate (ARC); if no ARC, a passport and
          a  Record of ID No. in the Republic of China are required.
          For branch-limited account holders, please visit your home branch.
    (2) Contact Customer Service Center:
          Just call us 24-hour toll-free hotline: 0800-700-365 to speak with a customer service officer
          (from a mobile, please dial: 04-23542030; from overseas, please call: +886-4-2354-2030).
    (3) Log into WebATM:
          Please use your Postal VISA Debit Card and a card reader via WebATM.  
          (https://webatm.post.gov.tw).  Select the option “ATM CARD FOR OTHER PURPOSES"

2. To increase the daily limit up to NT$100,000; no monthly limit:
    Only applying in person is allowed. You need to provide your national ID card, passbook, and
    authorized seal in person to any post office. A foreign national must present an Alien Resident
    Certificate (ARC); if no ARC, a passport and a Record of ID No. in the Republic of China are  
    required.For branch-limited account holders, please visit your home branch.

Please note:
After limit increase, the maximum overseas withdrawal limit per transaction still remains NT$20,000.
Temporary limit increase will be valid for 30 days from the application date.

If you find a suspicious charge, a payment amount error, or a certain unfamiliar transaction on your statement, please call our customer service center toll-free hotline: 0800-700-365 to speak with a customer service officer (from a mobile, please dial: 04-23542030; from overseas, please call: +886-4-2354-2030). Alternatively, you can visit a post office with your receipts or other evidential documents within 30 days after the day the current statement is sent.

Renewal application should be done 3 months prior to the card's expiration date. There are three ways for card renewal:  
(1) Applying in Person:
      Visit any post office near you with required application documents (for branch-limited account
      holders, please visit your home branch). See How to Apply for a Postal VISA Debit Card for
      required application documents.
(2) Online Renewal:
      You can renew your card either on our website (select VISA Debit Card, click Online Renewal),
      iPost, or WebATM.
(3) Auto-Renewal:
      If you have been using your Postal VISA Debit Card making purchases and overseas
      withdrawals in the most recent 7 months, no renewal application is required. Instead, your card
      will be renewed automatically and delivered to your registered address by mail 2 months
      before it expires.