Postage rates changed frequently in the early period after Hong Kong’s stamps were first issued, and existing denominations were unable to cover demand. As an ad hoc measure, the Hong Kong government sent stamps with outdated denominations to a local company to be overprinted as surcharged issues in order to plug the gap before stamps with new denominations arrived from Britain. In addition to being overprinted with new denominations, some Hong Kong stamps were also overprinted with the word CHINA from 1917 to 1921 (in the reign of King George V) to distinguish the Hong Kong stamps used at China’s trading ports from those used in the colony when the exchange rate increased between the currencies used in the two areas.

During Queen Victoria’s reign, stamp duty fiscals previously intended for fiscal and tax purposes were allowed to be used for postage until higher-denomination stamps became available from 1903 onwards in the reign of King Edward VII. This exceptional case was only repeated one other time: five-cent stamps were in great demand in the 1930s because they covered the postage between Hong Kong and mainland China, but following the death of King George V the 5-cent stamps featuring his portrait sold out as the British throne changed hands, and stamp duty fiscals temporarily stepped in to take their place in January 1938.