Mercez is an app (iOS only) that aims to help people save money when travelling internationally. It’s been getting a bit of attention recently (in this MMS review & this Out and Out review), I had planned to do a review of it awhile ago (when I was putting together our piece on foreign currency exchange rates, but the developer stopped answering questions when I was doing my write up). The app’s main aim is to save you money on foreign transactions by helping you select the best card to use.
It does this by allowing you to add credit cards you have to the app, then it looks at the following things:
- Any foreign exchange fees that these cards charge
- Exchange rates that vary by payment network
Unfortunately there is no way of knowing what exchange rate Visa, Mastercard or American Express will use ahead of time. What Mercez does is that it assumes that if a payment network has taken the lead for ‘best rate’ then it’s likely to keep that lead for 2-3 days. The problem with this is that most card issuers use the settlement date rather than the transaction date, so even if a payment network has ‘taken the lead’ when your transaction occurs – by the time the transaction has settled it might no longer be the best option (even if it keeps that lead for two or three days).
Mercez will also never suggest an American Express or Discover card as the best option, as those payment networks aren’t clear about what rate would be use. I’d love for this app to work as advertised, but I still think the best card to use is always going to be one that doesn’t charge a foreign currency fee and also offers a category bonus on whatever purchase you’re making.
You can try and fiddle with exchange rates as much as you like, but I still don’t think it’s as clear cut as apps such as these make it seem, or the other conventional wisdom of always using Mastercard over Visa. Let me know your thoughts about the app in the comments.
