While the other countries that maintained Treaty Ports with the Chinese overprinted the stamps of their home country for use in the Treaty Ports, Britain was alone in the decision to overprint a colonial issue. Although there had been discussions with the Hong Kong Government regarding a possible need for a separate issue of stamps for the Treaty Ports as early as 1911, the matter was first considered seriously in 1915 when the Postmaster General of Hong Kong, Mr. Wolfe, made a tour of the agencies and prepared a long and detailed report to the Post Office in London (GPO) dated 23 November 1915. This report laid out his justifications for the need for a separate issue for the Treaty Ports as opposed to continuing to use the Hong Kong stamps.
The primary reason for this need was to do with the fact that the Chinese dollar and the Hong Kong dollar were completely separate and the exchange rates between them had changed such that the Chinese dollar was only worth four-fifths that of the Hong Kong dollar. In other words, mail from Hong Kong itself was sent at the one penny rate, which translated to 4 Hong Kong cents and thus the repayment to the British was one penny. In the agencies, the same rate was being paid at 4 Chinese cents and so the British only received the equivalent of four-fifths of a penny. As the British postal agencies were already being run at a loss, which was absorbed by the British taxpayer and, with the costs of the First World War weighing heavily on everyone's mind, the need to separate the Hong Kong issues from the Treaty Port issues and thus bring the costs into parity became more desirable.
In addition 'people with a sharp eye to profit quickly realised that they could buy Hong Kong stamps in the treaty ports with depreciated Chinese money and then re-sell them to business houses in Hong Kong for Hong Kong dollars!' (HKSC 289/9)
In his letter to the GPO, Mr. Wolfe recommended that British stamps be surcharged to create the new Treaty Port issue. There was also at that time a suggestion by Mr. James Russell, who was the Postmaster General of Shanghai, in a letter dated 24 September 1915 that stamps be overprinted to encourage philatelists but Mr. Wolfe distanced himself from this as an incentive to create the issue.
On 15 March 1916, the GPO in London sent a letter to the Crown Agents stating that the Postmaster General wished 'to make arrangements for the issue of specially overprinted Hong Kong postage stamps for use by the British Post Office agencies in China.' In another letter, on 10 June 1916, the GPO wrote to the Board of Inland Revenue at Somerset House that 'the P.M.G. would be glad to know whether the necessary overprinting could be done by the Board's Stamping Department. Each stamp would be overprinted with the single word CHINA. The stamps will be purchased by this Department from the Crown Agents at cost price and the revenue derived from their sale will accrue to the Imperial and not to the Colonial Post Office.'
On 3 July 1916, Somerset House relied that the work could be undertaken in about three weeks.
On 18 July 1916 the GPO sent a progress report to Mr. Wolfe stating that arrangements were being made to overprint stamps for use by the Agencies and that a date would be fixed when regular Hong Kong stamps would no longer be valid for postage with unused stock being returned to Hong Kong and the new stamps would be used.
On 19 July 1916, De La Rue noted the request for the quantities to be printed for the Nil requisition, which were as shown in the link. From the above, we can possibly assume that 2 sheets of each stamp and 382 of the stationary were intended to be used for Specimen overprinting.
On 24 July 1916, the Crown Agents wrote to the GPO that instructions had been given to the printers, De La Rue, to execute the order and that a promise had been received to deliver the stamps in about 10 weeks time.
At some point before September Somerset House 'send to the GPO specimens of two types of overprint from an original choice of five: the one which was finally adopted, and a second with rather smaller and wider-spaced lettering. It would appear that some examples of this latter type must have been printed, since on 25th July, 1916 the G.P.O. wrote to the Stamping Department of Somerset House: 'We should be glad if you could let us have specimen overprints in each of the two types which you enclosed' (Perrin Page 6 )
Consequently, in September Somerset House sent to the Royal Mint a black proof sheet of adhesives with a request for two 240-set plates, and '2 or 3 separate electros of the word CHINA mounted on wood. The electros are for overprinting wrappers, postcards, etc.
Meanwhile there was discussion in the GPO as to the color of the overprint. At least one sheet of 50 cent stamps was overprinted CHINA in differing colors and, after examinations of the proofs in September 1916, it was decided that black would be acceptable as the color. An extraordinary recent discovery at the British Library turned up this sheet, folded and tucked away in an envelope (it has now been conserved) that shows the color trials of the overprints.
On 1 August 1916, the Crown Agents informed the Consular Office that Requisition 70/16 had been accepted but noted that, unless Hong Kong itself could use the overage, the 4c embossed envelopes would not be printed.
On 3rd August 1916, De La Rue responded that they could not prepare less than a quantity of 5,000 and so no 4c envelopes were ever printed. This was confirmed by the Crown Agents on 9th August 1916.
On 17th August 1916, De La Rue confirmed the final quantities to be printed under the requisition, which were as listed on this linked table.
