Is it true that if you apply for the tourist visa too early it may expire before the trip and you need to re-apply? How early is too early to apply for one? I'm planning on entering Thailand in 40 days from now (June 30).
TLDR : Answer Summary
Yes, if you apply for a tourist visa too early, it may expire before your trip, and you would need to re-apply. Typically, a Tourist Visa is valid for entry to Thailand for three months from the date of issue. Since you plan to enter in 40 days, applying closer to your travel date is advisable to ensure the visa remains valid.