ESTA with UK passport (valid > 10 years)

Since this seems to a date problem, check if you have entered the dates in the expected format:

• UK: TT/MM/YYYY
• US: MM/TT/YYYY
  • 31/01/2027 would be a valid UK date, but an invalid US date

Dialogs with Combo-Boxes, where the month must be selected, won't have this problem.

Care should also be taken to insure that the date of birth is correctly given:

• 07/08/1960 will be considered valid for both systems

but a mismatch could occur when comparing the ESTA (US format: July) data with the date stored inside the passport (August).

Another (unlikly) possibility is that the International Civil Aviation Organisation recommendation that the maximum passport validity of 10 years is being enforced by the ESTA program.

I could find no source confirming this:

Passport valid for travel to the United States – Your passport must be valid for at least six months beyond your period of stay in the United States (unless exempt by country-specific agreements).

There are, however, countries that would not consider the passport valid (see Schengen Border Code, Artical 6 below).

Update:
11 hours after this question was asked a second question was asked with the same problem

• usa - Is anyone having troubles filling out an ESTA form online?

I have a passport which was issued on Oct 26, 2011 and expires on Jul 26, 2022. Therefore it is valid for 10 years and 9 months.

Passport Issuance Date more than 11 years from the Passport Expire Date.

• This will probably cause some programer to blush...

A third reports says:

It is triggered by the year. For example the system works if you have a validity of 10 years 11 months if the dates run from say Jan 2015-Dec2025 but as soon as the year overlaps from 2015-2025 to 2015-2026 it will stop working.

Then it is subtracting the year numbers instead of counting the months and checking for > 132.

I have phoned them about this a couple of times and they are aware of the problem but have offered no resolution as of yet except apply for a visa or get a new passport. I am hoping they fix it as it is clearly a coding issue of some sort.

Have you tried contacting the CBP Info Center at (202) 325-8000 or 1-877-227-5511 for advice?

• Frequently Asked Questions about the Visa Waiver Program (VWP) and the Electronic System for Travel Authorization (ESTA) | U.S. Customs and Border Protection

Passports with validity over 10 years (5 years for children)
Since 2001, some adult British passports were issued with a validity longer than 10 years. If you renewed your passport before it expired, you were allowed to have the time left on your old passport added to your new passport. The maximum validity period possible was 10 years and 9 months. This means you can’t use the expiry date to check if your adult passport will be valid under the new rules.

Since the beginning of September 2018, extra validity was no longer added to passports. The maximum validity for an adult UK passport is now 10 years, and 5 years for a child passport. We have made this change to follow recommendations set out by the International Civil Aviation Organisation and to provide clarity about passport validity in the future.

• allthough the page containing this information has been withdrawn
  • this statement is, nevertheless, still valid

Article 6
Entry conditions for third-country nationals

(1) (a) (ii) it shall have been issued within the previous 10 years;

Note: this does not apply to UK passports presently (2019).

Sources:

• [Withdrawn] Travelling to the EU with a UK passport if there’s no Brexit deal - GOV.UK
  • This guidance was withdrawn on 28 January 2019
• Schengen Border Code

Its very likely a bug - I have had the same issue. It is triggered by the year. For example the system works if you have a validity of 10 years 11 months if the dates run from say Jan 2015-Dec2025 but as soon as the year overlaps from 2015-2025 to 2015-2026 it will stop working. I have phoned them about this a couple of times and they are aware of the problem but have offered no resolution as of yet except apply for a visa or get a new passport.

I have just been on the phone number listed above. My passport had 11 years 5 months. I was advised passport was good and it was a system error which was going to be fixed. The agent told me to try again in four days.