This permanently removes your ThaiCards account and everything attached to it. There is no undo.
Your email, display name, and sign-in are deleted.
All study progress, kept words, and review history are deleted.
If you have a paid subscription, cancel it first where you bought it: Google Play for Android purchases, Settings then your Apple Account then Subscriptions for iPhone purchases, or the Stripe billing portal for web purchases. Deleting the account does not cancel billing.