Can I cancel a Non-O year extension at the airport before flying out, or only at Chaeng Wattana?

It's possible to cancel a Non-O visa extension at the airport before flying out, but it's more commonly handled at the Chaeng Wattana Immigration Office. Some users reported cancelling their extensions at the airport directly, but experiences differ, with some advising to go through the immigration office to avoid issues with future visas. Leaving without a re-entry permit can also effectively cancel the extension, but this might lead to complications later.