Below is a list of currency systems or common trade standards which function like currency in the Solar System. This list includes not only the previously explained materials appearing in EP, but also some new ideas which might introduce local economic flavor to your game besides just tracking "credits".
Historic Earth coins minted of metal are used as a trade good or currency system in some places, and are harder to fake than bills or "old money". Specific coins in some amounts are considered "standard" for purposes of anonymous payment.
Aka "Inner System Credit", an electronic monetary system backed by all major capitalist factions. Credit can be transferred electronically, or through certified credit chips (which are anonymous). Some habs even use physical bills.
Cryptocurrency. It is acquired through anonymous services, can be transferred anonymously to another party and then is redeemed through a similar service. Has a 10% fee to transfer to or from Credit
Short for "Gigayen". This corporate scrip is issued by the corporate empire of Go-Nin group among all their employees and subsidiaries. While many employees are still paid in credits in some form, those working in Go-Nin run habitats, laboratories or exoplanet facilities may be paid all or partially in G-Yen instead, which can be spent at "company stores" for goods and services. G-Yen is almost entirely useless except to Go-Nin employees.
Currency used on habitat 500 Bushels. A bronze coin marked with the current government executive based on the year. Each Kerma has a value roughly equivalent to "One bushel" of product and thus is highly valued in their society.
Titanian currency, worth the approximate market value of 1 TB of qubits. This social currency is "paid" to microcorp workers under government charter and reinvested in other microcorps or social programs to drive the greater economy. Loopholes allow it to be converted to credit.
Aka "Mutualist Credit". These credits are issued and created at the moment of a transaction, thus acting like an interest-free loan. Has a 1-to-1 exchange with Credit, and Mutualists won't allow a person to get deep a negative balance to pay back.
Currency which only exists on the asteroid hab of Nova York. The Noyo begins devaluing immediately when issued - though the rate of devaluation is increased or decreased based on internal reputation metrics. Standard devaluation takes 1-2 months.
Pachinko is still a popular business/hobby in several parts of the Solar System, and their use of pellets or balls to get around many gambling regulations remains. This means that pachinko Pellets can easily double as a form of currency - with an exchange rate determined by your local pachinko business. This means that as a substitute for credit the value of a pellet is often determined by local business or criminal interests.
Groups like Nine Lives, or the habs they control like Legba, often accept transfer of Cortical Stacks or human egos as currency of a form. There is no exact price for an individual stack (though most have a minimum value floor) and it depends on the nature of the Ego inside the Stack.
Water tokens are an old form of currency, still utilized by some habitats or corporations who do not have perfect access to water. The token is a physical token or chit which is "valued" at a certain volume of (usually combinations of 1 liter) which can be exchanged with the local government or corporate venue in exchange for the amount of water. Since that volume of water can be calculated to have a cost, they might also be exchanged for other goods or services.