PAN non-compliance: penalty applies for failure to obtain or for quoting an invalid or incorrect PAN in required documents. Section 272B imposes a penalty where a person liable to obtain a PAN fails to obtain one, knowingly quotes an incorrect PAN in prescribed documents, or intimates an incorrect PAN to a person deducting or collecting tax. The provision covers both failure to comply with the PAN acquisition obligation and the separate obligation to quote a valid PAN, creating penalty exposure for quoting or intimating an invalid or incorrect PAN in required documents.