Joint and several liability of partners ensures personal responsibility for firm GST obligations; retiring partners remain liable until notified. Each partner and the firm are jointly and severally liable for tax, interest or penalty under the Uttarakhand GST Act. A retiring partner remains liable for obligations up to the date of retirement, and the partner or firm must notify the Commissioner in writing of the retirement date; failure to notify within one month extends the retiring partner's liability until the Commissioner's receipt of intimation.