B2 VISA Consulate Letter & Invitation Letter

Thanks for article - B1 Visitor Visa for Parents, B2 Business, Documents, Sponsorship - AM22 Tech

One Question do we need to sign Consulate Letter & Invitation Letter or we can just write our name?
Also I believer scan copy of this letter should work ?

Invitation letter has to signed by the person who is inviting.

Consulate letter should also be signed.

Thanks . Any idea if soft copy will work or I need to send original letters ?

Hi @KB_Patel

Original letters are required.