Money
Money or currency, sometimes called legal tender, was a medium of exchange used to facilitate transactions for goods or services. () Societies that used money were described as practicing currency-based economics. ()

Money on Earth 
Money was a common feature of life on Earth from the 16th century onward throughout the 19th, 20th, and 21st centuries.

According to Tom Paris, "nice clothes, [a] fast car, and lots of money" would be required in the Los Angeles of 1996. ()

The colloquialism "bucks" was still in use by 2032 to refer to money, specifically the American dollar. ()

In 2063, Zefram Cochrane explained to Commander Riker that his motivation for inventing the warp drive had been to get rich, describing "dollar signs" and money as his vision. ()

The New World Economy 
In the late 22nd century, the formation of the New World Economy on Earth led to the disappearance of money in the traditional sense on the planet. 23rd and 24th century Humans regularly referred to their species having developed a philosophy without the need for accumulation of wealth, instead focusing on self-enhancement and advancement of the Human race. (; ; )

During an excursion to 1986-era San Francisco, James T. Kirk told Spock about 20th century Earth, saying, "They're still using money. We need to get some." He then sold eyeglasses that Leonard McCoy had given him for $100. Later on, while Kirk was having dinner with Gillian Taylor in a restaurant and was unable to pay there, Gillian asked sarcastically, "don't tell me they don't use money in the 23rd century," and Kirk earnestly replied, "well, we don't." () 

In 2364, Jean-Luc Picard tried to explain to Ralph Offenhouse, a financier from the 20th century, that there would be no need for his services any longer. "A lot has changed in three hundred years," said Picard. "People are no longer obsessed with the accumulation of "things." We have eliminated hunger, want, the need for possessions." ()

When Lily Sloane asked Picard how much the  had cost to build, he told her, "the economics of the future is somewhat different. You see, money doesn't exist in the 24th century... The acquisition of wealth is no longer the driving force in our lives. We work to better ourselves and the rest of Humanity." ()

When Nog suggested that Jake should bid for a baseball card in an auction in 2373, Jake said, "I'm Human, I don't have any money." Nog commented, "It's not my fault that your species decided to abandon currency-based economics in favor of some philosophy of self-enhancement." Jake answered, "Hey, watch it. There's nothing wrong with our philosophy. We work to better ourselves and the rest of Humanity." Nog then replied, "What does that mean?" Jake responded, "It means... It means we don't need money!" Nog quickly pointed out, however, that Jake wouldn't be able to bid or borrow. ()

On a similar note, in 2374 Kathryn Janeway stated she was "not used to handling currency" while recounting her experience making a purchase in a market on the Mari homeworld. ()

Upon entering a holodeck simulation of an early-20th century bank in 2382, Beckett Mariner mocking asked to "withdraw some paper with no intrinsic value." ()

The Federation and money 
Outside of Earth, money and other forms of currency were still used in the 23rd and 24th century, by the Federation itself, individual Humans, and other Federation species. One form of such currency was the Federation credit.

The Human philanthropist Carter Winston acquired a vast personal fortune during the late 23rd century. ()

In 2368, a Vulcan master doubled the price of a meditation lamp upon learning that Tuvok and Kathryn Janeway were Starfleet officers. ()

Notably, the crew of the , faced with severe resource limitations after being flung into the Delta Quadrant, treated rations on replicator and holodeck use as currency and traded these among themselves. ()

Bartender Quark had repeated financial interactions with Federation personnel. On numerous occasions, Starfleet officers gambled to win latinum at Quark's, including Julian Bashir, Thomas Riker, and Jadzia Dax. (; ) His bar also routinely extended credit to its patrons, including Federation citizens and members of Starfleet. (; ) In 2372, he sold Quark's Treasure – a damaged Ferengi shuttle which had belonged to him – for scrap after it was disabled in the Sol system, and was given enough to cover passage back to Deep Space 9. () Later that year, Benjamin Sisko threatened Quark to collect on five years' "back rent" that was unpaid, though the actual motivation behind the threat was not fiscal. () Quark later stated that he was in debt to some unnamed Humans, but considered defaulting on them a trivial matter. () In 2373, he indirectly caused damage to a cargo bay, and was informed that he would have to bear the burden for the repairs, though it was not clear if this burden was financial in nature. () When Quark rescued  from a Federation starbase after he was arrested on Thalos VI, he had to pay a fine before he could be released. ()

Other mentions 
 Sometime in the 2250s, Harcourt Fenton Mudd programmed a number of  of himself with the phrase "if I had any money, I'd be sipping jippers on a beach somewhere." ()
 Captain Kirk offered to reimburse a group of miners on Rigel XII for lithium crystals in 2266, but he was rebuffed in favor of bartering for Mudd's women. ()
 In 2285, Leonard McCoy wanted to pay a smuggler to transport him to the . ()
 In 2364, Beverly Crusher bought a roll of cloth at Farpoint Station and had her account on the  billed. ()
 That same year, while playing the role of the title character in a Dixon Hill simulation, Picard stated a rate of $20 a day plus expenses to Jessica Bradley, who was convinced that someone was trying to kill her. She accepted and gave him a "c-note," or $100, as an advance. Later in the simulation, he wished to purchase a newspaper but did not have any money, and was told by the vendor that he could catch him next time. ()
 In 2366, Jean-Luc Picard purchased a Horga'hn on Risa. ()
 In 2368, Commander William T. Riker tried to get information out of Amarie. She complimented him on her husband and told him to "drop a few coins" in her jar. He told her that he did not carry any money, but managed to tempt her by teaching her a song. ()
 In 2370, when Lieutenant Worf and his son Alexander Rozhenko visited the Klingon outpost on Maranga IV, Alexander came to Worf asking for money, stating that he could see Molor's head in a box for 50 darseks. Worf replied that the man who told him this was just trying to take his money. ()
 As of the 24th century, the Bank of Bolias was a major financial institution, and Bolarus IX had a market economy that fluctuated in value. ()

Money as a figure of speech 
In certain cases, references to money were made in a manner that were construed or explained as euphemistic or idiomatic, with no literal implications of money directly being used:

 When preparing to fight Klingons on Organia in 2267, Kirk said, "Well, the Federation has spent a lot of money on our training." ()
 On two occasions later that year, Kirk commented to a subordinate, "You just earned your pay for the week!" ()
 That same year, Cyrano Jones, after giving a free tribble to Lieutenant Nyota Uhura, told her, "A tribble is the only love that money can buy." ()
 Shortly before he retired in the 2290s, Montgomery Scott stated that he had "just bought a boat." ()
 Leonard McCoy responded to  incessantly declaring quotations of William Shakespeare during the battle of Khitomer by saying, "I'd give real money if he'd shut up." ()
 Phillipa Louvois suggested to Picard, at a meeting in 2365, that he "buy [her] dinner." ()
 In 2366, an illusory representation of Rishon Uxbridge referred to her husband Kevin Uxbridge as a "starving student" when she had first met him. ()

 While inside the Nexus, Kirk described an illusion to Picard, remarking, "It's my house... I sold it years ago." Kirk was actually referring to a former home of his on Earth. ()
 In 2374, a smiling Jake Sisko mentioned to Quark that he had "sold [his] first book" earlier that day. Seemingly surprised, Quark asked Jake how much he had acquired from the sale of the book, to which Jake further explained, "It's just a figure of speech. The Federation News Service is going to publish a book of my stories about life on the station under Dominion rule." Jake then confirmed that he had not been paid. ()

Monetary units 
Beryllium (Grid 539)
Bolian currency (Bolian)
British pound (Old Britain)
Casino chip (Earth)
Cent (United States of America)
Coin (various)
Credit card (Earth)
Credit chip (Earth)
Darsek (Klingon Empire)
Dilithium (various)
Dime (United States of America)
Dirak (Karemma)
Dollar (United States of America)
Dorak (Barkon IV)
Federation credit (United Federation of Planets)
 (Earth)
Franc (France)
Frang ()
Gambling token (Earth)
Gold-pressed Latinum (various)
Isik (various)
 ()
Lek (Cardassian Union)
Lita (Bajoran Provisional Government)
Looney (Canada)
Penny (Canada, Old Britain, United States of America)
Quatloo (Providers of Triskelion)
Reichsmark (Germany, 1924-1948)
Renn (Mari)
Replicator ration ()
Scudo (Italy)
Shilling (England, Ireland)
Terran Imperial credit (Terran Empire)
Transporter credit (United Federation of Planets)
Voucher (various)

Appendices

See also 
 Credit
 Credit card
 Credit chip

Background information 
In the final draft script of , self-appointed "Captain" Kevin Riley, while suffering from polywater intoxication, announced to the crew of the  that all male crewmen who attended an upcoming formal dance would be "raised one pay grade." According to Riley, this was to compensate them for all the female crewmen who attended the event each being provided with a pint of perfume from ship's stores.

In the final draft script of , Doctor McCoy jokingly told Captain Kirk that, if McCoy was permitted to "just sit quietly in the background and hear" Kirk give Charles Evans a disciplinary talk, he "would gladly give up a year's pay."

The final draft script of  implied that the society on  involved money, as a wig scripted to be worn by Jahn was described (in one of the teleplay's stage directions) as having a price tag still attached while the wig was being worn.

Ronald D. Moore commented, "By the time I joined TNG, Gene had decreed that money most emphatically did NOT exist in the Federation, nor did 'credits' and that was that. Personally, I've always felt this was a bunch of hooey, but it was one of the rules and that's that." 

A cut scene in the script of  would have established that, as of 2063, "no one" had used currency in ten years, apparently due to scarcity. However, a currency called Dome money was also mentioned.

In the first draft script of , when Ryan became surprised that  could synthesize a required amount of valve seals in approximately forty minutes, Tucker joked that he could take longer to do so but that he "charge[d] by the hour."

An ultimately omitted line of dialogue from the final draft script of  featured 21st century Human  exclaiming to 22nd century Vulcan T'Pol, "You act like money doesn't mean anything!"

Roberto Orci and Alex Kurtzman, screenwriters of  and , said in a question-and-answer session with fans that "there's money, or some kind of credit system" in the alternate reality.

Apocrypha
There are many mentions of payment and currency in the  Balance of Power by Dafydd ab Hugh.

In the mirror universe of the alternate reality-set comic "Live Evil",  mentions a monetary unit called the "chit". 

In the 25th-century timeline of Star Trek Online, a currency system called "Energy Credits" (EC) has achieved near-universal acceptance among galactic powers, including the Klingon Empire and Romulan Star Empire. EC may be exchanged by individuals or traded for goods and services, and many commodities have a fixed EC "cost" to obtain from a replicator. It is implied that EC are intended as a direct representation of the amount of energy used to replicate or construct a given item, allowing commodities to become "cheaper" if they can be created for less energy. It is not known whether EC is used at large in the same way as regular currency, or if it is simply a convenient way for the game to facilitate more traditional economic activity.

External links

de:Geld
fr:Monnaie
Economics
Currency
Earth currencies