One payment log for the trip

Create columns for JPY price, chosen payment currency, estimated TWD and final TWD equivalent. Put a hotel deposit authorization and the final stay charge on separate lines so you do not count both as completed spending. Link a refund’s amount/date to the original purchase reference. Before departure, mark uses requiring a mobile wallet or backup physical card.

Give hotels, shopping and transport separate rows

Give hotel bookings, local shopping and transport spending separate rows because billing timing and cancellation conditions differ. A hypothetical JPY30,000 hotel booking recorded only as “travel spending” tells you little about whether the amount authorized at reservation matches the amount ultimately settled after the stay.

Save the booking currency, the currency actually chosen at checkout and the final card entry. Use the same reservation conditions in a card comparison, and do not mix refundable and non-refundable room prices. That lets you distinguish a cheaper payment route from a cheaper booking with a different cancellation trade-off.

Close the comparison after settlement

Do not finish the exchange-rate comparison with the authorization notification received during the trip. Use the final statement to express JPY spending in TWD and add the issuance or plan costs allocated to this trip. Keep unreceived rewards in an estimate column, separate from amounts actually credited.

If you return a purchase after arriving home, link the refund date and amount to the original transaction. Check whether currency differences remain and whether original charges were returned. That produces a clearer picture of the whole trip than comparing headline cashback percentages alone.