Sales tax liability is independent of registration timing, and best-judgment assessment can cover the full taxable period.

Liability to sales tax under the Bihar Sales Tax Act, 1947 arises from the charging provision and is not controlled by the timing or validity of a registration application. Section 13(5) operates as assessment machinery, permitting best-judgment assessment where a dealer liable to tax fails to apply for registration or furnish required particulars. Read with the power to call for returns from unregistered dealers under section 12(1) and Rule 20, the provision supports assessment for the full period of taxable business activity, including periods when the dealer was unregistered. The assessment for the entire period was therefore held valid.

---

---

Issues: Whether an assessment under section 13(5) of the Bihar Sales Tax Act, 1947, is valid for the entire period of taxable business activity notwithstanding that the dealer applied for registration during part of that period.

Analysis: Section 4 is the charging provision and creates the liability to sales tax. Section 13(5) is a machinery provision enabling assessment to the best of judgment where the Commissioner is satisfied that a dealer liable to tax has failed to apply for registration or furnish required particulars. The liability to pay tax does not depend on the validity or timing of the registration application. To read section 13(5) as restricting assessment until registration would nullify the charging provision and produce an unreasonable result, leaving an unregistered dealer in a better position than a registered dealer. The power to require returns from unregistered dealers under section 12(1) and Rule 20 supports the view that assessment machinery applies to unregistered dealers as well.

Conclusion: The assessment under section 13(5) for the whole period was valid, and the question was answered against the assessee and in favour of the State.

Ratio Decidendi: Liability created by a charging section is not dependent on registration, and a provision authorising assessment of unregistered dealers operates as assessment machinery rather than as a condition precedent to tax liability.

---