Born about 1810 in Scotland, Allan joined the Hudson's Bay Company in 1830 as a clerk. He served at York Factory and Norway House before being posted to Fort Vancouver where he served as an accountant from 1834 to 1842. He was transferred to the Sandwich (Hawaiian) Islands where he served as a joint agent with George Pelly, and was appointed Chief Trader there in 1845 and served in that capacity until 1847 when he was replaced by Dugald McTavish. In 1848 his request for a promotion to Chief Factor was denied and he retired. Subsequently, he formed a business partnership (Allan, McKinlay and Co.) and established himself as a merchant in Oregon. He died in 1890.