Changing the Finance settings
To edit your currency settings click ‘Settings’ in the sidebar.
From there, you will find the 'Financial Settings' under the Account category.
Better Proposals isn’t a financial system but it does display your sales pipeline and it only makes sense to show you in the currency you trade in. To change your currency, click the drop down box and select the one you like.
Document Currency and Taxes
If you want to change the default currency you display on your documents or switch taxes on/off, follow the instructions here for editing your branding.