In 1919 the Japanese Posts introduced “Postage Fee Paid” forms. These forms were used to pay for various kinds of mail matter in bulk. The official Japanese postal term was 郵便料金受領証原符 = “Postage fee reception original form” and is imprinted on top. The actual mail items received a circular bisected handstamp in characters “(post office name)/postage fee separately paid” (…/料金別納). The postage fee was pasted to the forms, which where kept by the accepting post office for a prescribed storage period. The advantages were: for the customer, one did not have to paste a postage stamp to each single mail item, and for the post office workers, they did not have to postmark each single mail item with small denomination stamps, but just paste the full amount in higher value stamps on one form.
Introduced in Japan 1919.4.20 (Taisho 8.4.20)* as kittebetsunoyubin 切手別納郵便 (stamps paid separately mail). The entire postage was paid by stamps, often a whole sheet or a large block of stamps. By 1938.5.1 (Showa 12.5.1), cash payment became possible – postage stamps were still pasted to the forms, but in the case of cash payment, the stamps were from the post office’s own stamp stocks. Consequently the system was renamed ryokinbetsunoyubin 料金別納郵便 (“postage fee paid separately mail”). For international mail, the UPU named this system in French “Taxe Perçue” (T. P.) and it was introduced in Japan and territories on 1930.7.1.
This kind of bulk mail handling was continued by Korea Post and is still used today. Current forms and markings are with hangul syllabics, of course.
April 1946 usages from Seoul Kanghwamun (光花門) post office
There are more forms from this postal archive run postmarked March-May, 1946, almost all showing non-overprinted stamps. This probably means that the usage of the USAMGIK issued chon-surcharge stamps was shortlived, even at the large Kanghwamun P.O., probably due to small actual numbers, while sufficient non-overprinted old Japanese stamps in higher denominations were in stock. Non-overprinted old stamps were redrawn from counter sale after 1946.4.30 and became demonetized after 1946.6.30. USAMGIK surcharge stamps became invalid for postage after the same date.
* Spaulding, Dr. Robert M.: “Postage Paid Separately. IN: Japanese Philately Vol. 55, No. 3 (August 2000) p. 113.