How to reach us
For partnerships, advertising, corrections, and error reports, email us at:
You can also reach us through our Naver blog.
What helps us help you
- The page URL with the problem
- The sentence or calculation step that looks wrong
- An official source URL and the date you checked it
Please don't send passwords, order numbers, phone numbers, or other personal information.
Scope
UsefulBasis can't guarantee that a package will be accepted by a specific carrier or that a seller will meet your expectations. For individual order or delivery disputes, contact the seller or carrier.