Rectification power cannot add penal interest where omission may reflect lawful discretion under a retrospective proviso.

Rectification under Section 35 is confined to patent mistakes apparent from the record and cannot be used as a review or revision power. Where the assessment order's omission to levy penal interest under Section 18A(6) could reasonably be attributed either to a failure to apply the law or to a lawful exercise of discretion under the proviso, the omission is not a clear apparent error. The retrospective fifth proviso and Rule 48 required the proviso to operate fully from the earlier date, so the officer could have waived or reduced interest. Rectification was therefore not competent.

---

---

Issues: Whether the Income-tax Officer could invoke rectification powers to add penal interest under Section 18A(6) when the assessment order had omitted to levy it, and whether such omission constituted an error apparent on the face of the record.

Analysis: The power of rectification under Section 35 is confined to correcting mistakes apparent from the record and is not a power of review or revision. An error of law can be rectified if all relevant facts are already on the record and no further enquiry is required. However, where the assessment order can reasonably be explained either by a failure to apply the law or by an exercise of discretion under the proviso to Section 18A(6), the omission cannot safely be treated as a patent mistake. The retrospective introduction of the fifth proviso, coupled with Rule 48, created a legal fiction under which the proviso had to be given full effect from the earlier date. That fiction meant the officer could have exercised discretion to reduce or waive the interest, and the absence of any reference to penal interest in the original order could not be treated as a clear and undeniable breach of statutory duty.

Conclusion: The omission to levy penal interest was not an error apparent on the face of the record, and rectification under Section 35 was not competent. The petition succeeded.

Ratio Decidendi: Rectification is permissible only for a patent mistake discernible from the record, and where a retrospective proviso and discretionary waiver provision make the omission of interest reasonably referable to a lawful discretion, the omission cannot be treated as a rectifiable error of law.

---