If I sell to customers in other countries, can my portal show prices in their own currency?

Yes, your portal can show prices in more than one currency, but it helps to understand the difference between what your customer sees on screen and what their card is actually charged. Most flight and hotel suppliers return fares in their own currency, so the portal converts that into the currency your customer is browsing in. You decide which currencies to offer, and you can usually add a small buffer to the conversion so that a movement in the exchange rate does not eat into your margin. Those rates refresh on a schedule rather than second by second, so a published rate can be slightly behind the live market.

The actual charge depends on your payment provider, not on the portal. Some gateways can accept payment in several currencies and settle everything into one account for you, while others only charge in a single currency and let the customer's own bank do the conversion. That second arrangement still works fine, but your customer may see a slightly different amount on their statement than the one shown at checkout, and they may pay their bank's conversion fee. It is worth deciding which approach you want before you start advertising abroad.

Refunds follow the same path. Money normally comes back in the currency it was taken in, so if rates have moved since the booking, a refunded amount can differ a little from what was originally paid. That is how card networks and banks handle it rather than something we control, so it is better to explain it to your customer upfront than to be surprised later.

The practical next step is to list the countries you plan to sell to, then ask your payment provider which currencies it can accept and settle into your account, and share that with us so we can set up the display currencies and conversion buffer to match.