What should I do if my Non-Immigrant ED Visa application was canceled due to a mistake in the course dates?

🚨 Hi everyone, I urgently need your help regarding the Non-Immigrant ED Visa for Thailand. 🚨

I applied for the ED visa online yesterday, and unfortunately received the message "Your visa application has been cancelled" just a few hours later.

The application fee was already paid, but unfortunately it’s non-refundable.

I wasn’t told the reason for the rejection, but when reviewing my documents I noticed that I had made a mistake in my initial application.

I had accidentally written the course period as July 2025 to November 2026, which would of course exceed the normal visa period. Even though the official school letter clearly says July 2025 to November 2025. I've now corrected that mistake.

However, I’m still unsure if there’s another issue.

According to the school's letter, the program starts on July 26, 2025, but my planned arrival in Thailand is only in September 2025.

Could this timing mismatch be the reason for the rejection?

Is it a problem if the course officially begins before I enter the country?

I’d really appreciate your help:

* What are the most common mistakes with the ED visa application?

* When specifying the duration of stay, do I need to match the course dates exactly, or only my personal travel dates?

* Do I already need to have a return flight booked for the visa to be approved, even if I plan to extend my stay later?

* What should I pay extra attention to?

* Has anyone had a similar experience and can give me advice?

Unfortunately, I can’t contact the embassy until Monday by phone or email.

Until then, I’d be really thankful for any tips or insights 🙏