Hi. I can&#x27;t speak to the specifics of the YC letter, but in general, a B1 visa letter should contain the following 3 elements. The letter should emphasize throughout, that the applicant won&#x27;t receive any payment from a US source (except expenses), and won&#x27;t perform any work in the US.<p>1. A STATEMENT OF THE PURPOSE OF THE VISIT, WITH A DETAILED US ITINERARY.
The B1 rules contain a list of acceptable B1 visitor activities. These include the following: &quot;Participation in professional conferences&quot; and &quot;Observing the conduct of US business or professional activity.&quot; The letter should be framed to fit the &quot;purpose of your visit&quot; into one or both of these categories.<p>This part should also include the following: Specific, definite, and realistic plans for the entire period of the visit. A US travel itinerary listing dates, locations, and where you will stay.<p>2. PROOF OF YOUR INTENTION TO DEPART THE US, PLUS EVIDENCE OF TIES ABROAD.
This section explains your specific plan for departure from the United States. Examples: I have a round-trip ticket for departure from the US on X date. I am required to speak at a conference in home country on Y date.<p>This part also lists your personal and business ties to your home country, as proof of your intention to depart the US. Examples include: Family home with spouse and children; spouse&#x27;s employment and children&#x27;s school enrollment. Deeds or titles to real property, vehicles, other valuable assets. Leases. Meaningful business or financial connections. Permanent employment or career. Job offer. Extended family ties. Community, social, or cultural associations.<p>3. FINANCIAL RESOURCES.
A detailed explanation of why you won&#x27;t need to work, or seek public assistance, during your visit to the United States, with a specific list of assets. Examples might include: A statement from the accelerator of what travel and lodging expenses they are paying. Your bank statements showing personal assets. A relative’s letter stating that all financial support will be provided.<p>The B1 letter should have all the listed evidentiary items attached to it, such as invitation and schedule for accelerator program, travel and lodging itinerary, round-trip ticket, future commitments abroad, ties to home country such as deeds &#x2F; assets &#x2F; family connections, and proof of financial resources.<p>IAAL but this isn&#x27;t legal advice. HTH