Provisional assessment: require prompt provisional assessments and refunds; withholdments only after senior approval. Provisional assessments under Section 141A should be made and refunds granted promptly where requested or where returned income and pre-assessment tax indicate a refund and regular assessment is unlikely within six months. Large provisional refunds may be withheld only with prior Commissioner approval under Section 241. All cases under Section 141A and applications or returns exceeding the specified threshold must be entered in a dedicated register kept in the ITO's personal custody and reviewed periodically to ensure timely provisional assessments and refunds.