diff --git a/CHANGELOG.md b/CHANGELOG.md
index cc7b0f06..81d5d07c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## 2026-11-10 - Sponsor WhatsApp message names Border Pulse (draft)
+
+- The sponsor card's WhatsApp button now opens a prefilled message saying the patient found the clinic on Border Pulse (EN/ES). The visitor can edit it before sending. This lets the business see the source in its own inbox, which analytics cannot show.
+- Checks: full `npm test` passes after a prerendered build.
+
 ## 2026-11-10 - Sponsor link goes to the live clinic site; bolder CBP report time (draft)
 
 - The Constandse sponsor card now links to the clinic's live site (constandse-dental.vercel.app) instead of its preview deployment.
diff --git a/src/components/sponsors/SponsoredCard.jsx b/src/components/sponsors/SponsoredCard.jsx
index 6923cdb5..00b7ad91 100644
--- a/src/components/sponsors/SponsoredCard.jsx
+++ b/src/components/sponsors/SponsoredCard.jsx
@@ -32,7 +32,7 @@ export default function SponsoredCard({ sponsor, placement, language = 'en' }) {
         </a>
         {sponsor.whatsapp && (
           <a
-            href={`https://wa.me/${sponsor.whatsapp}`}
+            href={`https://wa.me/${sponsor.whatsapp}${sponsor.whatsappText ? `?text=${encodeURIComponent(sponsor.whatsappText[es ? 'es' : 'en'])}` : ''}`}
             target="_blank"
             rel="sponsored noopener"
             onClick={() => log('whatsapp')}
diff --git a/src/lib/sponsors.js b/src/lib/sponsors.js
index 22c6bb7d..0d634682 100644
--- a/src/lib/sponsors.js
+++ b/src/lib/sponsors.js
@@ -14,6 +14,11 @@ export const SPONSORS = [
     },
     url: 'https://constandse-dental.vercel.app/',
     whatsapp: '19153007751',
+    // Prefilled so the business sees where the patient came from.
+    whatsappText: {
+      en: 'Hi, I found your clinic on Border Pulse and would like to book an appointment.',
+      es: 'Hola, encontré su consultorio en Border Pulse y quiero agendar una cita.',
+    },
     // Ciudad Juárez crossings: PDN, BOTA, Ysleta, Stanton DCL, El Paso (combined).
     ports: ['240202', '240201', '240104', '240204', '240221'],
     guides: [