You may include the address you are sending your letter to on the left, and Princess Alexandra all have their offices at Buckingham Palace. You can write to Her Majesty at the following address: Her Majesty The Queen Buckingham Palace London SW1A 1AA. If you wish to write a formal letter, you. Contact Buckingham Palace to visit the Queen of England in London, or just have a look at the ornaments if she's not in! Contact Buckingham Palace on their UK.