Pre-paid mail in the 1930s and 1940s

Generally speaking, stamps were not used to pre-pay postage of bulk postings of mail at main post offices. Cash would have been paid, and then a special datestamp inscribed Készpénzzel Bérmentesitve in red was applied to each item to indicated that pre-payment had been made. This example comes from Debreczen 2, is dated 14 November 1933, and has a local delivery address.