The volume of taxed mail matter handled continually increased. As part of the preparation to join the Universal Postal Union, the Postal Administration made plans to print postage-due stamps in accordance with the stipulations of the Universal Postal Convention. However, before the printing of such stamps, the London Print Coiling Dragon definitive stamps were overprinted for temporary use as postage-due stamps. The overprint bears the Chinese wording"欠資"in No.5 Sung character and the English wording "Postage Due" arranged in two lines across the middle part of the stamps.The whole set consists of six denominations and there is no change in their original face value.