The highest denomination of the postage-due stamps printed in various issues was 30* in value. As higher-value stamps were required following revisions of the postage rates and the fact that parcels were sometimes also liable to tax, the one-dollar and two-dollar denominations of Dr. Sun Yat-sen definitive stamps of the Hongkong Dah Tung Print were altered to become postage-due stamps, with No. 4 Sung characters "暫作欠資"(temporarily used as postage-due stamp)overprinted in four sides by the printing Bureau of the Dah Tung Book Co., Hongkong.