Unbound currently take payment in GBP (£), EUR (€) and USD ($).
If you're making your first pledge you can change the currency on the project page before you choose your reward. See the images below for more details.
Once you have completed your pledge we save your currency preference as a cookie, so from now on all prices will be shown in your preferred currency.
If you want to change your preferred currency for any reason, just head over to your Account Settings and follow steps 1, 2 and 3 below.