Is your registration under ESTA due to expire?
If you wish to travel to the United States under the terms of the Visa Waiver Program, your registration under ESTA must be valid up to and including the day on which you enter the United States. Your registration under ESTA does not need to be valid for the entire length of your stay in the United States, or for a specific period after you leave.
Please note, however, that if you will make a side trip to Canada, Mexico or the adjacent islandsand you will re-enter the United States on your return journey, your ESTA registration must be valid on re-entry.
A registration under ESTA is valid for two years from the date it is authorized or until the date on which the traveler’s passport expires, whichever comes first. You can check the status of your registration, or submit a new registration, by visiting the official ESTA website at https://esta.cbp.dhs.gov