diff --git a/.server-changes/invite-email-case-insensitive.md b/.server-changes/invite-email-case-insensitive.md
new file mode 100644
index 00000000000..ea238588482
--- /dev/null
+++ b/.server-changes/invite-email-case-insensitive.md
@@ -0,0 +1,6 @@
+---
+area: webapp
+type: fix
+---
+
+Org member invites now match emails case-insensitively, so an invite whose email casing differs from the invitee's account email can be accepted. Re-inviting an already-invited email now resends the invite instead of failing.
diff --git a/apps/webapp/app/models/member.server.ts b/apps/webapp/app/models/member.server.ts
index 3be5f7ce09c..bbbe14db167 100644
--- a/apps/webapp/app/models/member.server.ts
+++ b/apps/webapp/app/models/member.server.ts
@@ -134,7 +134,12 @@ export async function inviteMembers({
   const existingMembers = await prisma.orgMember.findMany({
     where: {
       organizationId: org.id,
-      user: { email: { in: [...uniqueEmails] } },
+      user: {
+        email: {
+          in: [...uniqueEmails],
+          mode: "insensitive",
+        },
+      },
     },
     select: { user: { select: { email: true } } },
   });
@@ -203,7 +208,7 @@ export async function getInviteFromToken({ token }: { token: string }) {
 export async function getUsersInvites({ email }: { email: string }) {
   return await prisma.orgMemberInvite.findMany({
     where: {
-      email,
+      email: { equals: email, mode: "insensitive" },
       organization: {
         deletedAt: null,
       },
@@ -562,7 +567,7 @@ export async function acceptInvite({
     await prisma.orgMemberInvite.delete({
       where: {
         id: inviteId,
-        email: user.email,
+        email: { equals: user.email, mode: "insensitive" },
       },
     });
   } catch (error) {
@@ -573,6 +578,15 @@ export async function acceptInvite({
     }
   }
 
+  // Consume any case-variant duplicate invites for this org (rows created
+  // before invite emails were lowercased)
+  await prisma.orgMemberInvite.deleteMany({
+    where: {
+      organizationId: invite.organizationId,
+      email: { equals: user.email, mode: "insensitive" },
+    },
+  });
+
   const remainingInvites = await getUsersInvites({ email: user.email });
 
   if (invite.rbacRoleId) {
@@ -605,7 +619,7 @@ export async function declineInvite({
     const declinedInvite = await tx.orgMemberInvite.delete({
       where: {
         id: inviteId,
-        email: user.email,
+        email: { equals: user.email, mode: "insensitive" },
       },
       include: {
         organization: true,
@@ -615,7 +629,7 @@ export async function declineInvite({
     //2. check for other invites
     const remainingInvites = await tx.orgMemberInvite.findMany({
       where: {
-        email: user.email,
+        email: { equals: user.email, mode: "insensitive" },
       },
     });
 
diff --git a/apps/webapp/app/routes/_app.orgs.$organizationSlug.invite/route.tsx b/apps/webapp/app/routes/_app.orgs.$organizationSlug.invite/route.tsx
index b6fe0b09c68..54127c22f38 100644
--- a/apps/webapp/app/routes/_app.orgs.$organizationSlug.invite/route.tsx
+++ b/apps/webapp/app/routes/_app.orgs.$organizationSlug.invite/route.tsx
@@ -123,7 +123,7 @@ const schema = z.object({
     }
 
     return [""];
-  }, z.string().email().array().nonempty("At least one email is required")),
+  }, z.string().trim().toLowerCase().email().array().nonempty("At least one email is required")),
   rbacRoleId: z.string().optional(),
 });
 
diff --git a/apps/webapp/app/routes/invite-accept.tsx b/apps/webapp/app/routes/invite-accept.tsx
index 592384b9515..b777ea393d5 100644
--- a/apps/webapp/app/routes/invite-accept.tsx
+++ b/apps/webapp/app/routes/invite-accept.tsx
@@ -34,7 +34,7 @@ export async function loader({ request }: LoaderFunctionArgs) {
     );
   }
 
-  if (invite.email !== user.email) {
+  if (invite.email.toLowerCase() !== user.email.toLowerCase()) {
     return redirectWithErrorMessage(
       "/",
       request,