Can I show prices on my website in my customer's own currency as well as mine?

Yes, in most cases you can show prices in more than one currency, although what is possible depends on your suppliers and your payment gateway. The usual setup is that your software has one base currency, which is the currency you are billed in and the one your reports are built on, and then one or more display currencies that your customers can switch between on the website.

The way it normally works is that the supplier sends back a price in whatever currency it trades in, the software converts that into the currency your customer has chosen using an exchange rate, and your markup and service fee are applied on top. You can usually choose whether the rate is updated automatically or whether you set it yourself, and many agencies add a small cushion to the rate so that movement in the market does not eat into their margin.

The honest limit is at the payment stage. Even when the website displays a converted price, the actual charge may be taken in the currency your gateway and your supplier settle in, and the customer's own bank may apply its own conversion, so the amount on their statement can differ slightly from the figure they saw. Some suppliers also only confirm and refund in their own currency, which matters when a cancellation comes back later at a different rate.

Before you turn this on, check with your payment provider which currencies it can actually collect, and decide whether you want to carry the exchange risk yourself or pass it to the customer at checkout.