It’s important to have your token sale structured to be able to accept the most common currencies. Currently, the most accepted currencies during STOs are USD/EUR, ETH and BTC. Fiat currencies are rapidly becoming the most important as investors are afraid of the high volatility of cryptocurrencies. A Security Token Offering can be done without accepting any cryptocurrency, in order to facilitate the compliance for example.
If the company that is issuing the security token needs to invest in real world assets they will need to convert part or the totality of the crypto-currencies received from investors into fiat. If the token currency base is in fiat, you will need to apply a fair and clear conversion rate and notify your investors on how the conversion rate is calculated and used.
For conversion between fiat currencies, the banks usually integrate the service and can describe their exchange rate rules.
The price of your token should be based in a single currency. This helps to reduce volatility and ensure fairness between investors, a fiat currency such as USD or EUR is generally used.
For a Security Token Offering a company may want to have the ability to accept multiple forms of payment. For fiat payments, the issuer should be able to accept bank transfers in several currencies. Specific payment providers can be used as well (bank card, Paypal, etc.) but it will cause additional fees for the issuer.
For payments in crypto, smart contracts or dedicated wallet systems can be set up.