In 1889, he became the Queen's and Lord Treasurer's Remembrancer, an office of the Court of the Exchequer which was originally concerned with the recovery of dues, penalties, and debts owed to the Crown.

After a further unsuccessful attempt to be elected to Parliament in 1911 he retired from public life and became a director of Shell, the first of several directorships he held.

[4] Sir Reginald became 27th Chief of Clan MacLeod in 1929 on the death of his elder brother Norman Magnus.

An expert from the Victoria and Albert Museum discussed with Sir Reginald the possible origins of the flag, avoiding reference to the supernatural.

His daughter Olive was noted for her journey of 3,700 miles (6,000 km) into the heart of Africa in 1910–1911 to visit her fiancé's grave.