diff --git a/src/app/api/auth/register/route.ts b/src/app/api/auth/register/route.ts
index 764e861..d66f193 100644
--- a/src/app/api/auth/register/route.ts
+++ b/src/app/api/auth/register/route.ts
@@ -66,12 +66,18 @@ export async function POST(req: NextRequest) {
 
     const hashedPassword = await bcrypt.hash(password, 12);
 
+    // Invite-based signups have already proven email ownership by clicking the
+    // tokenized link we sent to that exact address, so we mark the email as
+    // verified up-front and skip the post-registration verification email.
+    const isInviteSignup = !!inviteOrgId;
+
     const user = await prisma.user.create({
       data: {
         email,
         displayName,
         hashedPassword,
         role: "viewer",
+        emailVerified: isInviteSignup ? new Date() : null,
       },
     });
 
@@ -119,14 +125,20 @@ export async function POST(req: NextRequest) {
       }
     }
 
-    try {
-      const baseUrl = new URL(req.url).origin;
-      await sendVerificationEmail(email, baseUrl);
-    } catch (emailErr) {
-      console.warn("[register] Verification email failed (non-blocking):", emailErr);
+    if (!isInviteSignup) {
+      try {
+        const baseUrl = new URL(req.url).origin;
+        await sendVerificationEmail(email, baseUrl);
+      } catch (emailErr) {
+        console.warn("[register] Verification email failed (non-blocking):", emailErr);
+      }
     }
 
-    return NextResponse.json({ success: true, userId: user.id });
+    return NextResponse.json({
+      success: true,
+      userId: user.id,
+      emailVerified: isInviteSignup,
+    });
   } catch (error) {
     console.error("[register] Error:", error);
     return NextResponse.json(
diff --git a/src/app/api/invitations/verify/route.ts b/src/app/api/invitations/verify/route.ts
index ee24083..3780b30 100644
--- a/src/app/api/invitations/verify/route.ts
+++ b/src/app/api/invitations/verify/route.ts
@@ -1,10 +1,36 @@
 import { NextRequest, NextResponse } from "next/server";
 import { prisma } from "@/lib/db";
 
+type VerifyFailure = {
+  valid: false;
+  reason: "not_found" | "expired" | "accepted";
+  orgName?: string;
+  inviterName?: string;
+};
+
+type VerifySuccess = {
+  valid: true;
+  email: string;
+  role: string;
+  orgName: string;
+  inviterName: string | null;
+  hasExistingAccount: boolean;
+};
+
+async function resolveInviterName(invitedById: string): Promise<string | null> {
+  const inviter = await prisma.user.findUnique({
+    where: { id: invitedById },
+    select: { displayName: true, username: true, email: true },
+  });
+  if (!inviter) return null;
+  return inviter.displayName || inviter.username || inviter.email || null;
+}
+
 export async function GET(req: NextRequest) {
   const token = req.nextUrl.searchParams.get("token");
   if (!token) {
-    return NextResponse.json({ valid: false });
+    const body: VerifyFailure = { valid: false, reason: "not_found" };
+    return NextResponse.json(body);
   }
 
   const invitation = await prisma.invitation.findUnique({
@@ -12,8 +38,31 @@ export async function GET(req: NextRequest) {
     include: { organization: { select: { name: true } } },
   });
 
-  if (!invitation || invitation.acceptedAt || invitation.expiresAt < new Date()) {
-    return NextResponse.json({ valid: false });
+  if (!invitation) {
+    const body: VerifyFailure = { valid: false, reason: "not_found" };
+    return NextResponse.json(body);
+  }
+
+  const inviterName = await resolveInviterName(invitation.invitedById);
+
+  if (invitation.acceptedAt) {
+    const body: VerifyFailure = {
+      valid: false,
+      reason: "accepted",
+      orgName: invitation.organization.name,
+      inviterName: inviterName ?? undefined,
+    };
+    return NextResponse.json(body);
+  }
+
+  if (invitation.expiresAt < new Date()) {
+    const body: VerifyFailure = {
+      valid: false,
+      reason: "expired",
+      orgName: invitation.organization.name,
+      inviterName: inviterName ?? undefined,
+    };
+    return NextResponse.json(body);
   }
 
   const existingUser = await prisma.user.findUnique({
@@ -21,11 +70,13 @@ export async function GET(req: NextRequest) {
     select: { id: true },
   });
 
-  return NextResponse.json({
+  const body: VerifySuccess = {
     valid: true,
     email: invitation.email,
     role: invitation.role,
     orgName: invitation.organization.name,
+    inviterName,
     hasExistingAccount: !!existingUser,
-  });
+  };
+  return NextResponse.json(body);
 }