You should try to avoid the situation where your ESTA expires while in the USA
but if it does happen, it only has consequences if you overstay the 90-day limit. So, even if your
ESTA expires part way through your trip, as long as you have not overstayed the limit, there are no
consequences to this.
If your ESTA does expire during your trip, this will not negatively affect your future travels to
the U.S., as long as you do not overstay the 90 days that the Visa Waiver Program grants you.
However, be aware that whilst your ESTA does not need to be valid for the entirety of the duration
of your stay,
your passport must remain valid up until your departure and for six months afteryour arrival.
The reason you should try to plan your trip so that it is not close to your ESTA expiry date
is in case your flight is delayed for some reason and
your ESTA expires before you get to the US border control. In this case, the airline will
usually decline entry onto the plane as they know that you do not have the
relevant authorisation to enter the US. If your ESTA is approaching expiry it is a good
idea that you apply for a new one before your trip, as it will just supersede the previous one,
you don’t need to wait forone to expire before you apply for a new one.
If you have had a new passport issued since you applied for your ESTA
ESTA will no longer be valid. An ESTA
is linked to the passport details that you provide
at application and an ESTA cannot be transferred from one passport onto another, a whole
new ESTA is required