Show Cause Notice for GST assessment: explain why tax, interest and penalty should not be imposed for unregistered business. Form GST ASMT 14 is a show cause notice for assessment under section 63, alleging failure to obtain registration and discharge tax liabilities, and possibly cancellation under sub section (2) of section 29. It directs the recipient to show cause why tax with interest should not be created and why penalty should not be imposed for conducting business without registration, and specifies the date, time and place to appear before the issuing officer.