The German word Visum is close enough to visa, visto and visado that travellers from many countries grasp it at once, while it still sounds distinctive. Paired with bitcoin, it suggests borderless money meeting the very bordered world of travel documents. The .com ending is the default commercial address worldwide, which suits a service whose customers are, by definition, on the move between countries and currencies.
Swiss and German versions of the name are available too and can be bought as a set, so a global brand could run regional pages for Switzerland and Germany. Fitting projects include a travel agency settling bookings in bitcoin, a portal for digital nomads comparing long-stay options, a newsletter on residence programmes and an onboarding service that treats a first bitcoin purchase as an entry visa.