Question about onward flight. A friend of mine is going to do this trip:

- Go: MAD - CNX (via HKG)

- Back 3 weeks later: PNH - MAD (via HKG)

Both flights operated with the same company (Cathay), and bought together.

As she is entering Thailand by air, with a 30 days exemption, should she has an onward flight/train/whatever from Thailand? Or, if asked, it's pretty clear that she is returning to her home?

My doubt is because she has a (real, not fake) return-to-home flight, but it's not from Thailand, but from Cambodia.

The check-in will be online, so I think there is no problem with the company.

But a bit worried about the inmigration at Chiang Mai if they ask for an onward flight...

We're going to leave Thailand just a few days after their arrive, crossing to Lao to do the slow boat to Luang Prabang, so no bus/train tickets...

Do you think it's worth to book some bus or train out of Thailand? Or will it be enough with the flight from Phnom Pehn to her home country?

Thanks in advance!