When a hotel's real currency differs from the one displayed on a booking site, there's a conversion happening behind the scenes — and it's rarely done at the same rate your card network would use if you paid directly. Booking platforms typically apply their own markup to the displayed exchange rate, on top of whatever rate they got from a currency provider.
This markup is usually small on a per-unit basis, often in the low single-digit percentages, but it compounds with everything else in the price — taxes, service fees, and the room rate itself all get converted through the same marked-up rate. On a multi-night stay in a different currency zone, that can add up to a real, if easy to miss, difference.
The cleanest way to check is to compare the price shown in the hotel's local currency against the same price auto-converted to your home currency, when the platform offers both views. A gap that's noticeably wider than typical bank exchange spreads is a signal the platform's conversion is doing some of the work of the markup.
It also means comparisons across platforms should be done in a consistent currency. Two platforms showing prices in different currencies for the same room can look like a real gap when part of it is just conversion methodology — always convert both to the same currency before deciding which is actually cheaper.
