Visa-free entry to Thailand
Citizens today are allowed to visit Thailand, for a period not exceeding 30 days without issuing special visas.
You can safely take a ticket to the plane, and on the border of Thailand to issue a symbolic visa.
It is important at the same time to remember that the passport must be valid for at least 6 months from the date of your departure back. There must also be an air ticket available.
The only restriction in this case - within 3 months, you can thus be in Thailand no more than 3 times (90 days).
Crossing the border, you may be required to confirm financial solvency, so it is better not to hide some cash or payment cards.
So also the passport should be in a neat condition. Negligent handling of documents can be an excuse to fly back without being blown to Thailand