  Your ESTA travel authorization is valid for two years from the date of issue or until your passport expires.  The expiry date of your ESTA is mentioned in the document you received.  Once you have your ESTA authorization, you may have multiple trips within a two-year period from the date of the approval.  This means that if you have obtained an ESTA authorization to travel, you do not need to request it again since you are still within the validity period of the authorization.  Note: it is essential to print a copy of this document. Although it is not required to have the printed version upon arrival in the United States since the agents receive all the necessary information electronically.  Having an ESTA document does not mean that you have the right to stay in the United States for 