Transiting through Seattle to Vancouver- ESTA needed?

[mmmunch]

Currently looking at a flight that lands in Seattle before an onward trip to Vancouver (and back to London direct from Vancouver 12 days later).

Will be in transit for about 3 hours, but with hand luggage only so we won't need to collect bags, exit and then go through check-in, security etc.

We are flying with AA/BA then jumping on an Alaskan Airways flight so I need to check if its the same terminal but would I require an ESTA for being in transit?

(my wife is Canadian so will travel on her Canadian passport rather than her UK one).

Has anyone done something similar recently and confirm if ones needed?

Thanks


M

[fiatpower]

Yes you need one to transit through the US