[4] In 1843, he was appointed Cantonese interpreter to the garrison[2]: 413n  and, two years later, to the Supreme Court of Hong Kong, and, in 1846, assistant Chinese secretary to the superintendent of trade, Sir John Francis Davis.

On the declaration of the Second Opium War in 1857, he was attached to Lord Elgin's staff as Chinese secretary and with the assistance of Horatio Nelson Lay he conducted the negotiations which led up to the Treaty of Tientsin (1858).

In the following year he accompanied Sir Frederick Bruce in his attempt to exchange the ratification of the treaty, and was present at Taku when the force attending the mission was attacked and driven back from the Hai River.

[4] On Lord Elgin's return to China in 1860, he resumed his former post of Chinese secretary, and was mainly instrumental in arranging for the advance of the special envoys and the British and French forces to Tianjin and subsequently towards Beijing.

For the purpose of arranging for a camping ground in Tongzhou he accompanied Mr (afterwards Sir) Harry Parkes on his first visit to that city.

Wade was appointed Envoy Extraordinary and Minister Plenipotentiary and Chief Superintendent of British Trade in China in that year and served in that role until his retirement in 1883.