Provisional assessment lets taxpayers pay tax provisionally pending final valuation and assessment. Provisional assessment allows a taxable person unable to determine value or tax rate to request written permission to pay tax provisionally; the proper officer must order provisional payment within ninety days and may require a prescribed bond with surety to secure any tax difference. A final assessment must be completed within six months, subject to specified extensions, and interest is payable on unpaid tax from the due date until actual payment; refunds arising from final assessment attract interest as provided by law.