diff --git a/site/public/order/dot-compliance/index.html b/site/public/order/dot-compliance/index.html
index 07edec9..54d4b98 100644
--- a/site/public/order/dot-compliance/index.html
+++ b/site/public/order/dot-compliance/index.html
@@ -442,25 +442,57 @@ var checkboxes = document.querySelectorAll("input[data-slug]");
 var totalSection = document.getElementById("pw-total-section");
 var totalRows = document.getElementById("pw-total-rows");
 
+// Non-discountable slugs (passthrough costs)
+var nonDiscountable = {"dot-drug-alcohol": true};
+
+// Cached discount info
+var activeDiscount = null;
+function fetchDiscount() {
+  var code = (document.getElementById("pw-promo").value || "").trim().toUpperCase();
+  if (!code) { activeDiscount = null; updateTotal(); return; }
+  fetch(API + "/api/v1/discount/" + encodeURIComponent(code)).then(function(r) { return r.json(); }).then(function(d) {
+    if (d.valid) { activeDiscount = d; } else { activeDiscount = null; }
+    updateTotal();
+  }).catch(function() { activeDiscount = null; updateTotal(); });
+}
+// Fetch on load if promo pre-filled
+if (promoFromUrl) { setTimeout(fetchDiscount, 500); }
+// Fetch on blur of promo field
+document.getElementById("pw-promo").addEventListener("blur", fetchDiscount);
+
 function updateTotal() {
   var selected = [];
   var svcTotal = 0;
   var govTotal = 0;
+  var discountable = 0;
   checkboxes.forEach(function(cb) {
     if (cb.checked) {
       var price = parseInt(cb.dataset.price) || 0;
       var gov = parseInt(cb.dataset.govfee) || 0;
       svcTotal += price;
       govTotal += gov;
+      if (!nonDiscountable[cb.dataset.slug]) { discountable += price; }
       selected.push(cb.dataset.slug);
     }
   });
   if (selected.length === 0) { totalSection.hidden = true; return; }
   totalSection.hidden = false;
 
+  var discountAmt = 0;
+  if (activeDiscount && activeDiscount.discount_type === "percent") {
+    discountAmt = Math.round(discountable * activeDiscount.discount_value / 100);
+  } else if (activeDiscount && activeDiscount.discount_type === "flat") {
+    discountAmt = Math.min(activeDiscount.discount_value * 100, discountable);
+  }
+
   var html = '<div class="flex justify-between text-sm mb-1"><span>' + selected.length + ' service' + (selected.length > 1 ? 's' : '') + '</span><span>' + usd(svcTotal) + '</span></div>';
   if (govTotal > 0) html += '<div class="flex justify-between text-sm text-gray-500 mb-1"><span>Government fees (passthrough)</span><span>' + usd(govTotal) + '</span></div>';
-  html += '<div class="flex justify-between font-bold text-lg border-t border-gray-300 pt-2 mt-2"><span>Total</span><span>' + usd(svcTotal + govTotal) + '</span></div>';
+  if (discountAmt > 0) {
+    html += '<div class="flex justify-between text-sm text-green-600 font-semibold mb-1"><span>' + activeDiscount.code + ' (' + activeDiscount.discount_value + '% off)</span><span>-' + usd(discountAmt) + '</span></div>';
+  }
+  var finalTotal = svcTotal + govTotal - discountAmt;
+  html += '<div class="flex justify-between font-bold text-lg border-t border-gray-300 pt-2 mt-2"><span>Total</span><span>' + usd(finalTotal) + '</span></div>';
+  if (discountAmt > 0) { html += '<div class="text-xs text-green-600 text-right mt-1">You save ' + usd(discountAmt) + '!</div>'; }
   totalRows.innerHTML = html;
 }