Credit (#) is an international currency used in several western countries of the world as well as Asian, South-American and African.
The currency started as a cryptocurrency used by military organisations after the nuclear phase of the Global War. The currency soon got the attention of the newly reformed World Trade Organization, which used it as what they called a "common ground currency" for new trade transactions. Several countries soon followed suit and made it their national currency due to many currencies falling in value.
Scholars are debating how the Hashtag became the credit symbol. There are a few theories, though. Due to the limited infrastructure after the nuclear phase of the Global War, the character needed to be simple. The symbol needed to be a well-established icon that all computers could already type. Hence the use of the hashtag. Other scholars claim that the reason could be because of one of the creators behind the Credit, namely general Solomon Hash and that the hashtag, therefore, could be a homage to the general.