postal draft
British (now historical )
noun
1In 1914 the form used at Post Offices for the payment of Navy and Army Separation Allowances, later called ‘allowance form’.
2A draft or cheque drawn on the Postmaster General, introduced in January 1925 for the payment of National Health Insurance benefits, and later extended to certain government departments.
Origin
1920s; earliest use found in Post Office Guide.