1AA British citizens will receive a response, non-British citizens will not. No correspondence of any kind is sent directly to Her Majesty. If addressing to any reigning king or queen, it is best not to send it directly to him or her but to their Secretary. Neither the King nor Queen will receive any correspondence until his or her secretary has sorted it or opened it or both. If the invitation is to go to a reigning king and queen or any married sovereign, you must send separate invitations.
Sovereigns have separate secretaries and often have separate itineraries.
The address would also be changed. Personal correspondence for the staff of the Royal Family is sent to their private home and not to the Palace. Correspondence may be sent directly to His Holiness. All Rights Reserved.