Director liability for unpaid GST: directors of private companies are jointly and severally liable unless exempted by proof of no gross neglect. Directors of a private company are jointly and severally liable for unpaid tax, interest or penalty where recovery from the company is not possible, unless they prove the non-recovery is not due to their gross neglect, misfeasance or breach of duty; if the company converts to a public company and outstanding tax for the private period could not be recovered before conversion, the primary directorial liability does not apply, but personal penalties on directors remain enforceable.