Will my payment be treated as a “cash advance”?

There is a chance that your bank may charge an additional fee if they decide to treat your transaction as a cash advance. Most of the time, this can occur if you use a credit card for the purchase rather than a debit card.

Simplex does not charge additional fees apart from the processing fee, which is already included in the total cryptocurrency amount you will receive.
The card issuer controls the cash advance fee, like any other additional fee (international transaction, currency conversion, etc.).
It would be best to contact your bank directly to get more information about any additional fees you might encounter.