Start with purchases that actually qualify

A Taiwan household might spend NT$30,000 each month, but that is not automatically NT$30,000 of reward-eligible card spending. Separate transfers, cash purchases, ordinary online card-number payments and supported phone-wallet transactions. Use your own receipts to identify the amount that meets the specific promotion’s rules. Do not move an entire household budget into the calculation merely to reach a reward target.

Pro currently lists 3% on qualifying Apple Pay/Google Pay spending, capped at 18 USDs monthly, with US$12.90 monthly membership. USDs expire after 30 days. Treat these terms as inputs checked on the source date, then confirm them before subscribing. The example below assumes you can spend every earned credit on purchases you already intended to make.

Work through the cap and the costs

Assume NT$19,200 of qualifying spending and an illustrative rate of NT$32 per USD. That is US$600; multiplying by 3% produces 18 USDs, exactly the cap. Spending more under these same assumptions would not increase that month’s capped reward. The exchange rate is invented for arithmetic, and this is not a measured return or a recommendation to spend more.

The maximum credit is worth NT$576 only under our full-use assumption. Subtract NT$412.80 for the monthly membership at the same assumed rate: NT$163.20 remains before other costs. Now assume NT$250 of combined funding and transaction costs for this spending. The result becomes minus NT$86.80. That NT$250 is an example cost budget, not either provider’s quoted fee.

• Gross usable credit: NT$576.
• Less membership NT$412.80 and assumed costs NT$250.
• Illustrative net benefit: −NT$86.80.

Compare the alternative and the next month

Suppose your existing card would return a net 1% on precisely the same NT$19,200, with all its relevant costs already included. That alternative is worth NT$192, making the additional benefit of switching minus NT$278.80 in our example. Replace this assumption with your actual card result; a higher headline percentage has not answered the question of which route leaves you better off.

Repeat the calculation for a lower-spend month and a month containing a refund. Keep membership charges, unused credits and reward reversals visible. Value a card voucher only if you actually need that card, and assess an annual plan over its full paid term. Your decision should survive ordinary months in Taiwan, not rely on repeatedly hitting the maximum possible reward.