Promissory note in the context of "Loan"

Paper money, often referred to as a note or a bill (North American English), is a type of negotiable promissory note that is payable to the bearer on demand, making it a form of currency. The main types of paper money are government notes, which are directly issued by political authorities, and banknotes issued by banks, namely banks of issue including central banks. In some cases, paper money may be issued by other entities than governments or banks, for example merchants in pre-modern China and Japan. "Banknote" is often used synonymously for paper money, not least by collectors, but in a narrow sense banknotes are only the subset of paper money that is issued by banks.

Paper money is often, but not always, legal tender, meaning that courts of law are required to recognize them as satisfactory payment of money debts.

In law, tangible property is property that can be touched, and includes both real property and personal property (or moveable property), and stands in distinction to intangible property.

In English law and some Commonwealth legal systems, items of tangible property are referred to as choses in possession (or a chose in possession in the singular). However, some property, despite being physical in nature, is classified in many legal systems as intangible property rather than tangible property because the rights associated with the physical item are of far greater significance than the physical properties. Principally, these are documentary intangibles. For example, a promissory note is a piece of paper that can be touched, but the real significance is not the physical paper, but the legal rights which the paper confers, and hence the promissory note is defined by the legal debt rather than the physical attributes.

Accounts receivable, abbreviated as AR or A/R, are legally enforceable claims for payment held by a business for goods supplied or services rendered that customers have ordered but not paid for. The accounts receivable process involves customer onboarding, invoicing, collections, deductions, exception management, and finally, cash posting after the payment is collected.

Accounts receivable are generally in the form of invoices raised by a business and delivered to the customer for payment within an agreed time frame. Accounts receivable is shown in a balance sheet as an asset. It is one of a series of accounting transactions dealing with the billing of a customer for goods and services that the customer has ordered. These may be distinguished from notes receivable, which are debts created through formal legal instruments called promissory notes.

Between the 9th and 14th centuries, the Muslim world developed many advanced economic concepts, techniques and usages. These ranged from areas of production, investment, finance, economic development, taxation, property use such as Hawala: an early informal value transfer system, Islamic trusts, known as waqf, systems of contract relied upon by merchants, a widely circulated common currency, cheques, promissory notes, early contracts, bills of exchange, and forms of commercial partnership such as mufawada.

Specific Islamic concepts involving money, property, taxation, charity and the Five Pillars include:

Jiaozi (Chinese: 交子) was a form of promissory note which appeared around the 11th century in the Sichuan capital of Chengdu, China. Numismatists regard it as the first paper money in history, a development of the Chinese Song Dynasty (960–1279 CE). Early Jiaozi notes did not have standard denominations but were denominated according to the needs of the purchaser and ranged from 500 wén to 5 guàn. The government office that issued these notes or the Jiaozi wu (Chinese: 交子務) demanded a payment or exchange fee (Chinese: 紙墨費) of 30 wén per guàn exchanged from coins to banknote. The Jiaozi were usually issued biannually.

In the region of Liang-Huai (Chinese: 兩淮) these banknotes were referred to as Huaijiao (淮交) and were introduced in 1136. Still, their circulation stopped quickly after their introduction. Generally the lower the denominations of the Jiaozi the more popular they became, and as the government was initially unable to regulate their production properly, their existence eventually led to undesirably high inflation rate.

An IOU (abbreviated from the phrase "I owe you") is usually an informal document acknowledging debt. An IOU differs from a promissory note in that an IOU is not a negotiable instrument and does not specify repayment terms such as the time of repayment. IOUs usually specify the debtor, the amount owed, and sometimes the creditor. IOUs may be signed or carry distinguishing marks or designs to ensure authenticity. In some cases, IOUs may be redeemable for a specific product or service rather than a quantity of currency, constituting a form of scrip.

Commercial paper, in the global financial market, is an unsecured promissory note with a fixed maturity of usually less than 270 days. In layperson terms, it is like an "IOU", but can be bought and sold because its buyers and sellers have some degree of confidence that it can be successfully redeemed later for cash, based on their assessment of the creditworthiness of the issuing company.

Commercial paper is a money-market security issued by large corporations to obtain funds to meet short-term debt obligations (for example, payroll) and is backed only by an issuing bank or company promise to pay the face amount on the maturity date specified on the note. Since it is not backed by collateral, only firms with excellent credit ratings from a recognized credit rating agency will be able to sell their commercial paper at a reasonable price. Commercial paper is usually sold at a discount from face value and generally carries lower interest repayment rates than bonds or corporate bonds due to the shorter maturities of commercial paper. Typically, the longer the maturity on a note, the higher the interest rate the issuing institution pays. Interest rates fluctuate with market conditions but are typically lower than banks' rates.