Provisional assessment permits taxpayers to pay tax provisionally with a bond, followed by final reassessment and interest obligations. If a taxable person cannot determine value or applicable tax rate, they may request provisional assessment in writing; the proper officer may allow provisional tax payment by specifying a provisional rate or value and may require a prescribed bond with surety or security to secure any difference. The proper officer must complete a final assessment within six months of the provisional order, subject to authorised extensions. Interest is payable on unpaid tax from the day after the statutory due date until actual payment, and refunds resulting from final assessment attract interest as provided by statute.