The Zagreb provisional issue was valid until July 1, 1945. However, usage was tolerated for the official needs of local and state institutions until their stock ran out. That happened sometime in the middle of July. Postage between official institutions was free of charge; only special handling was paid for.
1945 Zagreb provisional issue, express letter sent to the City National Committee locally in Zagreb (10.VII.45), franked with 160 kn for the express delivery. Late usage. Certificate Zrinjšćak.
Back side of the cover with the arriving cancellation (12.VII.45). Note that the main post office Zagreb 1 was using an old bilingual Latin and Cyrillic canceller from the Kingdom of Yugoslavia while the post office Zagreb 13 still used the Latin canceller from the Independent State of Croatia.
