Article 62 grants the Department authority over tax examination and assessment. It allows the Department to correct or adjust a tax declaration to ensure compliance with the law and to perform a tax assessment if a taxpayer fails to file. The Department must notify the taxpayer of any assessment and tax due via a registered letter or other verifiable means. Subject to Article 65, the Department can issue an additional assessment if a previously accepted tax amount is found to be incorrect. The taxpayer must be informed of the reasons and has the right to object to such an assessment.