Article 159 bis 21 integrates the small enterprise regime with the broader tax assessment framework. It mandates that several key assessment articles (Articles 135 bis, 143, 143 bis, 147-149 bis) apply to enterprises. This means the Authority can issue estimated assessments for non-compliance, apply deemed assessments if deadlines pass, and rectify or revise enterprise assessments within statutory time limits. By using the same legal machinery for assessments, the Law ensures that the Tax Authority has consistent powers to enforce tax liabilities across both small and large Omani businesses.