Vouchers definition in terms of Recording of Transactions - QS Study
QS Study

A voucher is a written document in maintain of a trade transaction. Vouchers are arranged by an accountant and each voucher is counteracting signed by an approved person of the organization.

A voucher is often a prenumbered form used in the accounts payable section to regulate and improve a company’s inside control over payments to its vendors and service providers. They are appropriately filed according to their sequential numbers so that the auditors might without difficulty vouch them and these may also serve as documentary proof in future.

Bills receivable, bills payable, wage sheet/salaries pay acquaintance, correspondence etc., also serve as the source documents. Thus, there must be a source document for each transaction recorded in the books of accounts.