Suppression in GST: willful non declaration or deliberate failure to furnish requested information triggers liability, subject to departmental knowledge. Suppression under CGST consists of non declaration of information required in statutory returns or failure to furnish information when writtenly requested by the proper officer. Liability demands a willful element: mere omission or inadvertence is insufficient; there must be deliberate conduct to evade payment. Intent to evade means conscious avoidance of a levy. Prior departmental knowledge of the facts, acceptance of disclosures, or nondisclosure of facts not legally required to be disclosed negates suppression.