The US authorities will start charging for ESTA applications soon

[AttilaTheMeerkat]

From September 8th a fee for ESTA applications will be applied. This will amount to $14 per person (about £9 currently).

If you are travelling to the US ensure your ESTA application (this is now mandatory) is completed before this time. ESTAs are valid for 2 years from date of issue.

Thanks for the useful info!
Do you need any proof that you have done ESTA online, e.g. registration number or anything else when you are travelling?

You can print out the ESTA approval for your own peace of mind once this is given but its not necessary to show the US immigration authorities on arrival.

Do only use the official US govt website though; there's plenty of people out there willing to take your cash for a service that is currently free.

thanks. DH has just done ours for our visit in October