We've had many questions here about dual citizens who for any number of reasons, might want to apply for an ESTA. Most notably, if the other country they belong to is either hostile to the USA or to the concept of dual citizenship and they do not want to let the departing country know they are American citizens, so they leave/board the departing country using that country's passport + ESTA (which lets AFIS to know they are allowed to board the airplane), and then enter the USA on their USA passport.
However, there seems to be mixed feedback on travel.stackexchange as to whether USA citizens are actually forbidden to get an ESTA on their second passport, although many in fact have done that - while declaring dual citizenship with the USA.
I can't actually find on the CBP website where it says that USA citizens are not allowed to have an ESTA. The closest is:
I am a U.S. Citizen with dual citizenship in a VWP country?
U.S. Citizens are not required to have an ESTA and are required to use their U.S. passport to travel to the U.S.
Not "required to have an ESTA" isn't the same as "you're not allowed to have an ESTA" -- and given that many people with multiple passports have gotten ESTAs despite declaring USA citizenship as well, suggests that it's permissible -- or at least inconsistently enforced in either direction.
Does someone have firmer evidence that it's actually impermissible to have an ESTA if you're a USA citizen?
p.s. Thee bit about "are required to use their US passport to travel to the US" is a little vague as well, but let's keep the questions and answers focused on whether you can apply for and have an ESTA (and not on whether you can use it).
- Can a US citizen leave and enter the US using a foreign passport? - this question is vague as it deals with exiting and entering with a foreign passport, my question deals with dual nationals who might leave their home country using their home passport + ESTA, but then enter the USA with their USA passport
- What is the penalty for dual US citizens who lie on the ESTA form in order to enter under VWP using their second passport? - note that this question deals with penalties for fraud, when my question assumes the ESTA is granted when the USA citizenship is noted