Later career
After his retirement, he remained active in public life, serving on several public bodies and commissions. Primrose was described as "a distinguished and valuable public servant, especially known for the clarity of his minutes and reports".
He was Chairman of the Commercial Pacific Cable Company from 1907 until 1914 and was a director of the Reversionary Interest Society from 1911.
Shortly after his retirement, he was appointed chairman of a royal commission to enquire into the financial relationship between the Supreme Government in India and the various provincial governments, although he resigned the appointment after a month, to be replaced by Sir Charles Hobhouse.
In 1911 he chaired a committee on the financial clauses of the Irish Home Rule Bill, a subject with which he had had experience since 1886. He proposed that an Irish government should have full control over its revenue, with the British government providing some additional funds to meet the deficit. His plan was rejected by Herbert Samuel, who drew up the financial clauses of the Home Rule Bill of 1912, as it was thought to offer excessive financial autonomy to the Irish.
In 1912, he was a member of the MacDonnell royal commission on the civil service and in 1913 of the Loreburn royal commission on railways.
In September 1914, Primrose was appointed chairman of the Welsh church commission consequent on Welsh disestablishment and of the commission set up to enquire into the supply of sugar after the First World War. In 1918 he was a member of the Bradbury committee on staff retrenchment in government offices.
In June 1912, he was sworn into the Privy Council, an unusual honour for a civil servant.
