Can my website show prices in my customers' local currency when the supplier rates come in another one?

Yes, in most cases your website can show prices in your customers' local currency even when the supplier sends its rates in a different one. The booking engine takes the rate it receives, applies a conversion, adds your markup and then displays the result. You can usually choose which currencies your site offers and which one is the default, so a customer in your home market sees familiar money instead of doing sums in their head.

The thing to be clear about is the gap between the currency your customer sees and the currency the booking is settled in with the supplier. The supplier may still invoice you in its own currency, so what finally leaves your account can move a little with the exchange rate. Which currencies are available, how often the conversion rate refreshes and whether you can add a small buffer of your own depends on the suppliers connected to your account and on your plan, so please check that rather than assume it.

Some charges are never converted. Taxes or fees paid at the hotel, airline charges for extras bought later and anything collected at the airport stay in the local currency of that place, and your customer's own bank may add a conversion charge on the card. Your invoices and reports can normally be produced in the currency you keep your books in, so your accounting stays tidy even when you sell in several.

A good next step is to write down the currencies you really need to sell in, then check which of those your connected suppliers support and how you want any conversion buffer handled before you go live.