There are thousands of complementary currency circuits in the world that support businesses/enterprises and consumers. In some countries, these circuits are so established and consolidated that a part of the economy thrives and is based on the economic exchanges that take place within the same circuit.
Before addressing and analyzing some of these circuits—and I will limit myself to mentioning just a couple, in particular those that in my opinion are the most effective on the national scene—it is first necessary to explain what complementary currency is:

Complementary currencies are means of exchange that exist alongside official currencies, without replacing them. They can be used to purchase goods or services and usually circulate in limited territories. Their circulation is not legal tender because they are not issued by the State

A historic circuit was born in Sardinia more than ten years ago and its name is SARDEX. Today, Sardex is present throughout Italy and is widely used in Sardinia. The companies that have joined the circuit have been able to face even difficult periods by relying precisely on commercial exchanges within the circuit, and many others have been able to develop and grow their business thanks to it. Commercial transactions take place exclusively between companies (b2b business to business) and private citizens are almost entirely excluded, except for a few initiatives that have not taken hold. Membership in the circuit requires payment of an annual fee, and results are quick to arrive for new members, since there are tens of thousands of companies in Sardex.

A brand new circuit that is emerging on the complementary currency scene is Monthica with its currency Etix.
Monethica has much in common with Sardex, particularly with regard to business-to-business (b2b) exchanges, but in addition to this, it introduces other innovations, including the involvement of citizens who can shop on the circuit's e-commerce platform using the free application and with a 30% increased purchasing power; For other important innovations that are part of the project and that I cannot address in this article, I refer you to the link of an interview with Prof. Vito Umberto Vavalli, inventor of Monethica.
Entry into Monethica for a company is subject to the payment of a one-time registration fee to be paid at the time of registration while citizens who wish to make purchases can download the application for free and are required to pay a €10/year fee for current account management costs because Monethica is currently the only Italian circuit that meets the traceability requirements requested by the Revenue Agency (for example: healthcare services paid in Etix from the PLUS account can be deducted)
But the question that naturally arises is why a company should join a credit circuit.
The answer is simple: joining a circuit would allow the company to "attract" new customers and consequently increase turnover, and also, with the proceeds, to reduce part of its current expenses by purchasing the necessary goods within the same circuit, thus being able to save Euros.