diff --git a/public/js/views/accounting-view.js b/public/js/views/accounting-view.js
index ff92af6..5a73c86 100644
--- a/public/js/views/accounting-view.js
+++ b/public/js/views/accounting-view.js
@@ -882,16 +882,17 @@ async function openTaxPeriodDetail(startDate, endDate, existingPeriod) {
             ${reportHtml}
 
             <div class="mt-4 border-t pt-4">
-                <div class="flex items-center gap-4 text-sm mb-3">
+                <div class="flex items-center gap-4 text-sm mb-3" id="st-summary-bar">
                     <span><strong>Tax Collected:</strong> ${fmtMoney(taxCollected)}</span>
-                    <span class="${adjustments !== 0 ? 'text-red-600' : ''}"><strong>Adjustment:</strong> ${adjustments > 0 ? `−${fmtMoney(adjustments)}` : adjustments < 0 ? `+$${Math.abs(adjustments).toFixed(2)}` : '—'}</span>
-                    <span class="text-lg font-bold text-gray-900"><strong>Net Due:</strong> ${fmtMoney(netPaid)}</span>
+                    <span id="st-adj-display" class="${adjustments !== 0 ? 'text-red-600' : ''}"><strong>Adjustment:</strong> ${adjustments > 0 ? `−${fmtMoney(adjustments)}` : adjustments < 0 ? `+$${Math.abs(adjustments).toFixed(2)}` : '—'}</span>
+                    <span id="st-net-due" class="text-lg font-bold text-gray-900"><strong>Net Due:</strong> ${fmtMoney(netPaid)}</span>
                 </div>
 
                 <div class="grid grid-cols-1 md:grid-cols-3 gap-3 mb-3">
                     <div>
                         <label class="block text-xs font-medium text-gray-700 mb-1">Adjustment Amount</label>
                         <input type="number" step="0.01" id="st-adjustment" value="${adjustments !== 0 ? adjustments : ''}" placeholder="e.g. 6.15 (discount)" ${isPaid ? 'disabled' : ''}
+                               oninput="window.accountingView.updateTaxPreview()"
                                class="w-full px-3 py-1.5 border border-gray-300 rounded-md text-sm">
                         <p class="text-xs text-gray-400 mt-0.5">Positive = discount (reduces net due)</p>
                     </div>
@@ -933,12 +934,13 @@ async function openTaxPeriodDetail(startDate, endDate, existingPeriod) {
 
                 ${!isPaid ? `
                 <div class="flex items-center justify-between border-t pt-3 mt-1">
-                    <div>
+                    <div id="st-je-lines">
                         <p class="text-sm"><strong>Journal Entry lines:</strong></p>
                         <p class="text-xs text-gray-500 font-mono">Debit Sales Tax Payable: ${fmtMoney(taxCollected)}</p>
                         ${adjustments > 0 ? `<p class="text-xs text-gray-500 font-mono">Credit Discount: ${fmtMoney(adjustments)}</p>` : ''}
                         ${adjustments < 0 ? `<p class="text-xs text-gray-500 font-mono">Debit Penalty: ${fmtMoney(Math.abs(adjustments))}</p>` : ''}
-                        <p class="text-xs text-gray-500 font-mono">Credit Bank: ${fmtMoney(netPaid)}</p>
+                        ${adjustments === 0 ? `` : ''}
+                        <p class="text-xs text-gray-500 font-mono" id="st-je-bank">Credit Bank: ${fmtMoney(netPaid)}</p>
                     </div>
                     <div class="flex gap-2">
                         <button onclick="window.accountingView.saveTaxPeriodDraft()"
@@ -969,6 +971,39 @@ export function closeTaxPeriodDetail() {
     stEditingPeriodId = null;
 }
 
+export function updateTaxPreview() {
+    if (!stCurrentTaxData) return;
+    const adjInput = document.getElementById('st-adjustment');
+    const adj = parseFloat(adjInput?.value) || 0;
+    const taxCollected = stCurrentTaxData.taxCollected;
+    const netPaid = taxCollected - adj;
+
+    const adjDisplay = document.getElementById('st-adj-display');
+    if (adjDisplay) {
+        adjDisplay.className = adj !== 0 ? 'text-red-600' : '';
+        adjDisplay.innerHTML = adj > 0
+            ? `<strong>Adjustment:</strong> −${fmtMoney(adj)}`
+            : adj < 0
+                ? `<strong>Adjustment:</strong> +$${Math.abs(adj).toFixed(2)}`
+                : `<strong>Adjustment:</strong> —`;
+    }
+
+    const netDue = document.getElementById('st-net-due');
+    if (netDue) {
+        netDue.innerHTML = `<strong>Net Due:</strong> ${fmtMoney(netPaid)}`;
+    }
+
+    const jeLines = document.getElementById('st-je-lines');
+    if (jeLines) {
+        jeLines.innerHTML = `
+            <p class="text-sm"><strong>Journal Entry lines:</strong></p>
+            <p class="text-xs text-gray-500 font-mono">Debit Sales Tax Payable: ${fmtMoney(taxCollected)}</p>
+            ${adj > 0 ? `<p class="text-xs text-gray-500 font-mono">Credit Discount: ${fmtMoney(adj)}</p>` : ''}
+            ${adj < 0 ? `<p class="text-xs text-gray-500 font-mono">Debit Penalty: ${fmtMoney(Math.abs(adj))}</p>` : ''}
+            <p class="text-xs text-gray-500 font-mono">Credit Bank: ${fmtMoney(netPaid)}</p>`;
+    }
+}
+
 export async function saveTaxPeriodDraft() {
     const adjAmount = parseFloat(document.getElementById('st-adjustment').value) || 0;
     const adjReason = document.getElementById('st-adjustment-reason').value.trim();
@@ -1191,6 +1226,7 @@ window.accountingView = {
     openNewTaxPeriod,
     openTaxPeriod,
     closeTaxPeriodDetail,
+    updateTaxPreview,
     saveTaxPeriodDraft,
     recordTaxPayment
 };
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