Complete and submit the form below. A formal invitation on your letterhead must also be attached.Gov​ no later than three weeks (3 weeks) prior to the meeting date. Complete the form below and submit at least 30 business days before the requested meeting or event. Clearly state what you are inviting the recipient to do and why it is important. Fill out and print out your personalized Letter of Invitation. For a formal letter invitation, it's best to explicitly point out the purpose, event goals, and the value it can bring to participants. Include meeting date and agenda item number or off-agenda item.