Vouch

A voucher is a bond of the redeemable transaction type which is worth a certain monetary value and which may be spent only for specific reasons or on specific goods. Examples include housing, travel, and food vouchers. The term and voucher is also a synonym for receipt and is often used to refer to receipts used as evidence of, for example, the declaration that a service has been performed or that an expenditure has been made.

The term is also commonly used for school vouchers, which are somewhat different.

Vouchers are used in the tourism sector primarily as proof of a named customer's right to take a service at a specific time and place. Service providers collect them to return to the tour operator or travel agent that has sent that customer, to prove they have given the service. So, the life of a voucher is as below:

This approach is most suitable for free individual tourist activities where pre-allocation for services are not necessary, feasible or applicable. It was customary before the information era when communication was limited and expensive, but now has been given quite a different role by B2C applications. When a reservation is made through the internet, customers are often provided a voucher through email or a web site that can be printed. Providers customarily require this voucher be presented prior to providing the service.

A voucher is an accounting document representing an internal intent to make a payment to an external entity, such as a vendor or service provider. A voucher is produced usually after receiving a vendor invoice, after the invoice is successfully matched to a purchase order. A voucher will contain detailed information regarding the payee, the monetary amount of the payment, a description of the transaction, and more. In accounts payable systems, a process called a "payment run" is executed to generate payments corresponding to the unpaid vouchers. These payments can then be released or held at the discretion of an accounts payable supervisor or the company controller.

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Wikipedia