diff --git a/server/api/series/[id]/tickets/purchase.post.js b/server/api/series/[id]/tickets/purchase.post.js
index bcf1ba9..740a752 100644
--- a/server/api/series/[id]/tickets/purchase.post.js
+++ b/server/api/series/[id]/tickets/purchase.post.js
@@ -44,9 +44,12 @@ export default defineEventHandler(async (event) => {
       member = await Member.findOne({ email: email.toLowerCase() });
     }
 
+    // Resolve canonical email: use authenticated member's email if available
+    const canonicalEmail = member ? member.email : email.toLowerCase();
+
     // Validate purchase
     const validation = validateSeriesTicketPurchase(series, {
-      email,
+      email: canonicalEmail,
       name,
       member,
     });
@@ -80,7 +83,7 @@ export default defineEventHandler(async (event) => {
     const registration = {
       memberId: member?._id,
       name,
-      email: email.toLowerCase(),
+      email: canonicalEmail,
       membershipLevel: member?.circle || "non-member",
       isMember: !!member,
       ticketType: ticketInfo.ticketType,
@@ -115,7 +118,7 @@ export default defineEventHandler(async (event) => {
     // Send confirmation email
     try {
       await sendSeriesPassConfirmation({
-        to: email,
+        to: canonicalEmail,
         name,
         series: {
           title: series.title,