In APM and the Clone Wars series, among other media, there are frequent instances where Republic credits are not accepted. These are typically places outside of the Republic and especially in the criminal underworld, Republic or otherwise.
If Anakin wants to pay Hondo to deliver some missiles illegally and not ask any questions, and Hondo does not accept credits, then what does Anakin pay him off with?
The primary currency of Tatooine (and the Outer Rim in general) was the Wupiupi
Apparently they're still in use by the time of the New Republic and the First Order
“Ha!” Pendewqell yawped. “I imagine you never heard the stories. Old pirates like to tell them after too many drinks in the cantinas. What was the most valuable of prizes during the Clone Wars?”
Reveth shrugged, her red lekku swaying back and forth. “Credits? Pre-Empire would be mostly worthless now…Aurodium?” she mused. “Wupiupi coins?”
Besides Republic/Imperial Credits, the other main currency in the galaxy is the Wupiupi, which is used mostly in the Outer Rim, especially by the Hutts. The CIS also issued their own version of the Credit.
Some tertiary currencies, such as the Druggat, exist. And some regularly traded commodities also stand in as currencies. At one point during the clone wars, Hondo wanted a ransom to be paid in Spice. And in Star Wars Rebels, Ezra remarks that a case of Nova Crystals would set him up for life.
Gems, Precious metals (usually in coins or Ingots), Wupiupi/Trugut/Peggat are major currencies in the outer rim, Most sectors or planets had a local form of currency as well. In addition to this most any high value, easily portable (and best illegal) commodity can be used as a makeshift currency such as spice. Though when using commodities as a barter currency expect to get fleeced on both ends of the "Exchange rate".
In The Mandalorian, we see Beskar Steel is quite valuable and sometimes used as currency in lieu of other forms of payment.
