What you see
The currency switcher changes what prices are shown in, everywhere on the site. It is a display conversion, done so you can judge whether something is worth it in money you think in.
What you are charged
Cards are charged in US dollars.
Where the operator prices their experience in a different currency, we convert it to dollars at the mid-market rate plus a spread, and the checkout shows you both: the operator's own figure, the rate used and the spread applied. The spread exists because converting a payment across currencies has a real cost, and it is written into the breakdown rather than hidden in the price.
Your bank may add its own
If your card is not a dollar card, your bank converts the dollar charge into your own currency at their rate, and many add a foreign transaction fee. That is between you and your bank; it is not ours and we never see it.
So the figure on your statement can differ slightly from the total on the checkout. If the difference looks larger than a bank's usual spread, send us the booking reference and the amount your statement shows and we will tell you exactly what we charged.