diff --git a/backend/src/routes/v1/auth.ts b/backend/src/routes/v1/auth.ts
index b633f82ea6..f373567f2c 100644
--- a/backend/src/routes/v1/auth.ts
+++ b/backend/src/routes/v1/auth.ts
@@ -11,7 +11,7 @@ router.post("/token", validateRequest, authController.getNewToken);
 router.post( // TODO endpoint: deprecate (moved to api/v3/auth/login1)
   "/login1",
   authLimiter,
-  body("email").exists().trim().notEmpty(),
+  body("email").exists().trim().notEmpty().toLowerCase(),
   body("clientPublicKey").exists().trim().notEmpty(),
   validateRequest,
   authController.login1
@@ -20,7 +20,7 @@ router.post( // TODO endpoint: deprecate (moved to api/v3/auth/login1)
 router.post( // TODO endpoint: deprecate (moved to api/v3/auth/login2)
   "/login2",
   authLimiter,
-  body("email").exists().trim().notEmpty(),
+  body("email").exists().trim().notEmpty().toLowerCase(),
   body("clientProof").exists().trim().notEmpty(),
   validateRequest,
   authController.login2
diff --git a/backend/src/routes/v2/auth.ts b/backend/src/routes/v2/auth.ts
index bf348c2792..e2d45f4525 100644
--- a/backend/src/routes/v2/auth.ts
+++ b/backend/src/routes/v2/auth.ts
@@ -8,7 +8,7 @@ import { authLimiter } from "../../helpers/rateLimiter";
 router.post( // TODO: deprecate (moved to api/v3/auth/login1)
   "/login1",
   authLimiter,
-  body("email").isString().trim().notEmpty(),
+  body("email").isString().trim().notEmpty().toLowerCase(),
   body("clientPublicKey").isString().trim().notEmpty(),
   validateRequest,
   authController.login1
@@ -17,7 +17,7 @@ router.post( // TODO: deprecate (moved to api/v3/auth/login1)
 router.post( // TODO: deprecate (moved to api/v3/auth/login1)
   "/login2",
   authLimiter,
-  body("email").isString().trim().notEmpty(),
+  body("email").isString().trim().notEmpty().toLowerCase(),
   body("clientProof").isString().trim().notEmpty(),
   validateRequest,
   authController.login2
diff --git a/backend/src/routes/v3/auth.ts b/backend/src/routes/v3/auth.ts
index 12afb51136..ba6f303358 100644
--- a/backend/src/routes/v3/auth.ts
+++ b/backend/src/routes/v3/auth.ts
@@ -9,7 +9,7 @@ const router = express.Router();
 router.post(
     "/login1",
     authLimiter,
-    body("email").isString().trim(),
+    body("email").isString().trim().toLowerCase(),
     body("providerAuthToken").isString().trim().optional({nullable: true}),
     body("clientPublicKey").isString().trim().notEmpty(),
     validateRequest,
@@ -19,7 +19,7 @@ router.post(
 router.post(
     "/login2",
     authLimiter,
-    body("email").isString().trim(),
+    body("email").isString().trim().toLowerCase(),
     body("providerAuthToken").isString().trim().optional({nullable: true}),
     body("clientProof").isString().trim().notEmpty(),
     validateRequest,
diff --git a/frontend/src/views/Login/components/InitialStep/InitialStep.tsx b/frontend/src/views/Login/components/InitialStep/InitialStep.tsx
index 08fc86fd93..7bab7414e6 100644
--- a/frontend/src/views/Login/components/InitialStep/InitialStep.tsx
+++ b/frontend/src/views/Login/components/InitialStep/InitialStep.tsx
@@ -45,15 +45,13 @@ export const InitialStep = ({
                 return;
             }
 
-            const sanitizedEmail = email.toLowerCase();
-
             setIsLoading(true);
             if (queryParams && queryParams.get("callback_port")) {
                 const callbackPort = queryParams.get("callback_port")
 
                 // attemptCliLogin
                 const isCliLoginSuccessful = await attemptCliLogin({
-                    email: sanitizedEmail,
+                    email: email.toLowerCase(),
                     password,
                 })
 
@@ -80,7 +78,7 @@ export const InitialStep = ({
                 }
             } else {
                 const isLoginSuccessful = await attemptLogin({
-                    email: sanitizedEmail,
+                    email: email.toLowerCase(),
                     password,
                 });
                 if (isLoginSuccessful && isLoginSuccessful.success) {