The payment system is an operational network - governed by laws, rules and standards - that links bank accounts and provides the functionality for monetary exchange using bank deposits. The payment system is the infrastructure (consisting of institutions, instruments, rules, procedures, standards,and technical means) established in effect the transfer of monetary value between parties discharging mutual obligations. Its technical efficiency determines the efficiency with which transaction money is used in the economy, and risk associated with its use.
What makes it a "system" is that it employs cash-substitutes; traditional payment systems are negotiable instruments such as drafts (e.g., checks) and documentary credits such as letter of credits. With the advent of computers and electronic communications a large number of alternative electronic payment systems have emerged. These include debit cards, credit cards, electronic funds transfers, direct credits, direct debits, internet banking and e-commerce payment systems. Some payment systems include credit mechanisms, but that is essentially a different aspect of payment. Payment systems are used in lieu of tendering cash in domestic and international transactions and consist of a major service provided by banks and other financial institutions.
A cashier's check (cashier's cheque, banker's cheque, bank cheque, official cheque, demand draft, teller's cheque, banker's draft or treasurer's cheque) is a check guaranteed by a bank, drawn on the bank's own funds and signed by a cashier. Cashier's checks are treated as guaranteed funds because the bank, rather than the purchaser, is responsible for paying the amount. They are commonly required for real estate and brokerage transactions.
When a customer asks a bank for a cashier's check, the bank debits the amount from the customer's account immediately, and then the bank assumes the responsibility for covering the cashier's check. This is in contrast with a personal check, where the bank does not debit the amount from the customer's account until the check is deposited or cashed by the recipient.
Cashier balancing is a process usually conducted in businesses such as grocery stores, restaurants and banks that takes place at the closing of the business day or at the end of a cashier's shift. This balancing process makes the cashier responsible for the money in his or her cash register.
A certified check or certified cheque is a form of check for which the bank verifies that sufficient funds exist in the account to cover the check, and so certifies, at the time the check is written. Those funds are then set aside in the bank's internal account until the check is cashed or returned by the payee. Thus, a certified check cannot "bounce", and, in this manner, its liquidity is similar to cash, absent failure of the bank or illegal act (such as the funds being based on a fraudulent loan, at which point the check will be disavowed).
In some countries, e.g. Germany, it is illegal for a regular bank to certify checks. This regulation is supposed to prevent certified checks from becoming a universal substitute for cash, which is considered the only legal tender. The Deutsche Bundesbank (Federal Bank) is the only financial institution authorized to issue certified checks.