Provisional assessment: allows provisional tax payment subject to bond, final assessment and interest obligations. When a taxable person cannot determine value or tax rate, they may request provisional assessment in writing; the officer must allow provisional payment by specifying a provisional rate or value and may require a prescribed bond with surety to secure payment of any difference. The officer must complete final assessment within a limited period subject to authorised extensions. Interest is payable on unpaid tax from the day after the usual due date until payment, and interest on refunds arising from the final assessment is payable under the refund provisions.