Since 1917, the Sovereign has sent congratulatory messages to people celebrating notable birthdays and anniversaries.
The Queen's congratulatory messages consist of a card containing a personalised message. The card comes in a special envelope, which is delivered through the normal postal channels.
Cards are sent to those celebrating their 100th and 105th birthday and every year thereafter, and to those celebrating their diamond wedding (60th), 65th, 70th wedding anniversaries and every year thereafter.
For many people, receiving a congratulatory card from The Queen to mark a significant birthday or wedding anniversary is a very special part of their celebrations.
The delivery of these messages is arranged by the Anniversaries Office, part of the Private Secretary's Office in the Royal Household, based at Buckingham Palace.
The Pension Service informs the Anniversaries Office of birthdays for recipients of UK State pensions. But, for data privacy reasons, there is no automatic alert from government records for wedding anniversaries.
Applying for a message
For the above reason, to make sure that a message is sent for birthdays and wedding anniversaries alike, an application to Buckingham Palace should preferably be made by a relative or friend in advance of the special day.
You can find more information and apply for a birthday or anniversary message on the GOV.UK website.