It must include the address, date, and time of the event on the left side of the letter.
Make sure to mention the salutation at the beginning and your signature at the ending of the letter.
Make sure to write a grammatically correct and concise letter.
It should indicate whether it is a formal or informal letter.
The host must express his or her warm welcome to the guests
Source: https://www.aplustopper.com/invitation-letter/#:~:text=Invitation%20Letter%20Writing%20Tips%201%20It%20must%20include,his%20or%20her%20warm%20welcome%20to%20the%20guests.
