O.H.M.S.

For the 1937 film, see O.H.M.S. (film).

Australian official mail, franked "On His Majesty's Service", crash cover salvaged from the 1935 Imperial Airways "City of Khartoum" aircraft crash at Alexandria during an England to Australia flight.

"On Her Majesty's Service" envelope with OHMS economy "Official Paid" label from 1978

O.H.M.S., an acronym for On Her Majesty's Service or On His Majesty's Service (depending on the gender of the reigning monarch) - is an official franking commonly seen on correspondence from government departments in countries of the Commonwealth of Nations, recognising the British monarch as the head of state.

In Canada, O.H.M.S may be written on an envelope instead of using postage stamps for any letters being sent to the Canadian House of Commons or to any member of the Canadian Parliament.^{[citation needed]}

In popular culture

O.H.M.S. is a 1937 action comedy film, while the title of Ian Fleming's 1963 James Bond novel On Her Majesty's Secret Service, and its film adapatation, is a play on the term.