Being a space opera setting, the economic systems of Hyperspace aren’t much different than in our world. They just operate on a much larger scale. From the free markets of the Solaris Republic and Akaylan Empire to the command-based XXX system, the economies of the Twin Spirals reflect what we are accustomed to in the real world. Various forms of capitalism, socialism and communism can be found throughout space, as well as more unusual economic systems in isolated areas.
Each stellar nation usually has its own form of money, though currency exchanges are common in trading areas. Most transactions are performed digitally, although some areas still produce tangible scrip, mostly for use in the Frontier. All digital currency cards and even physical notes are made of thin, durable plastics and contain a limited artificial intelligence which assists in completing transactions and preventing forgeries. Currency cards always display the amount carried on them, and are biometrically coded to discourage theft.
Note: A post-scarcity economy may be more realistic for a society this advanced, but it’s not in the spirit of two-fisted space opera. Familiar, real-world economies offer more opportunity for adventure (and profit).