Can international travelers use a UnionPay card for payments on Phu Quoc, Vietnam, and should they rely on it as their only payment method?

One traveler reports that a Rosselkhozbank UnionPay card is accepted at many businesses across Phu Quoc, potentially reducing the amount of US cash you need to carry.

Do not base your entire trip budget on a single UnionPay card: overseas functionality can be suspended unexpectedly, even if the card was working before departure.

For Phu Quoc, bring a reserve of US dollars and arrange a second way to pay. This avoids having to urgently find cash or borrow money if a card stops working.