Article 15 establishes a strict document retention policy for all taxpayers in Oman. Every taxpayer is legally required to preserve all registers, books of accounts, and supporting documents for a minimum of ten years following the end of the relevant accounting period. This includes all records used to prepare tax returns, evidence for computing taxable income, and documents necessary for determining tax on specific categories of income under Article 52. Maintaining these records is essential for potential audits or assessments by the Tax Authority within the statutory limitation period.