Numbers were allocated by a battalion or equivalent in 1914, so many shared the same number, even in one regiment or corps. In 1917 the Territorial Force was renumbered, so its members all received new numbers with six digits. If a man changed units he would be given a new number, so very many ended up having two, three or more numbers on their medal index cards.
Full renumbering of the army did not happen until the 1920s.
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