You may write a letter for your relatives inviting them to visit you. Include your family member's name, birth date, relationship to you, passport number.Complete the Invitation Letter form. Sample Invitation Letter. Date. Is there a performance, school event, or meeting to which you want to invite. Join us for a fun-filled day of joy and festivities. Include the Salutation. Write the Main Body of the Letter. Sample Invitation Letter for Inviting Relatives and Friends. (Date). Send an email to us requesting that we mail you a copy of your invitation letter.