Just an update on Chiang Khong. I just came back through. This was my 3rd land entry this calendar year. And second Chiang Khong crossing in a row. Last one was 30 days. This was 60.
It's now 1 night instead of 2. Laos still took 2000 THB for the VOA.
Thai immigration gave a document showing requirements to come back the next day.
10,000 THB, outbound flight to country of origin, and proof of accommodation in Thailand for duration of stay.
They didn't ask to see the 10k baht on the way back in. But he did take 5 minutes examining the plane ticket screenshot and was on his computer verifying it's legitimacy.
I showed my TM30 as proof of stay. He didn't pay much attention to it.
Make sure you have your plane ticket.
TLDR : Answer Summary
An update on the Chiang Khong border crossing reveals recent changes and requirements for travelers. After a third land entry this year, a traveler confirms that Thai immigration now requires a single night stay, with Laos charging 2000 THB for a Visa on Arrival (VOA). To re-enter Thailand, travelers need to show 10,000 THB, proof of accommodation for their stay, and an outbound flight ticket. Although immigration did not ask for the cash on re-entry, the authenticity of the flight ticket is verified. The travel community discusses varying visa requirements based on nationality and whether onward travel tickets are sufficient.