diff --git a/web/apps/accounts/src/pages/passkeys/verify.tsx b/web/apps/accounts/src/pages/passkeys/verify.tsx
index 29b20b2384..c9ea3289d9 100644
--- a/web/apps/accounts/src/pages/passkeys/verify.tsx
+++ b/web/apps/accounts/src/pages/passkeys/verify.tsx
@@ -16,6 +16,7 @@ import {
     isWebAuthnSupported,
     isWhitelistedRedirect,
     passkeyAuthenticationSuccessRedirectURL,
+    passkeySessionAlreadyClaimedErrorMessage,
     redirectToPasskeyRecoverPage,
     signChallenge,
     type BeginPasskeyAuthenticationResponse,
@@ -31,6 +32,7 @@ const Page = () => {
         | "loading" /* Can happen multiple times in the flow */
         | "webAuthnNotSupported" /* Unrecoverable error */
         | "unknownRedirect" /* Unrecoverable error */
+        | "sessionAlreadyClaimed" /* Unrecoverable error */
         | "unrecoverableFailure" /* Unrecoverable error - generic */
         | "failedDuringSignChallenge" /* Recoverable error in signChallenge */
         | "failed" /* Recoverable error otherwise */
@@ -117,7 +119,12 @@ const Page = () => {
             beginResponse = await beginPasskeyAuthentication(passkeySessionID);
         } catch (e) {
             log.error("Failed to begin passkey authentication", e);
-            setStatus("failed");
+            setStatus(
+                e instanceof Error &&
+                    e.message == passkeySessionAlreadyClaimedErrorMessage
+                    ? "sessionAlreadyClaimed"
+                    : "failed",
+            );
             return;
         }
 
@@ -231,6 +238,7 @@ const Page = () => {
         loading: <Loading />,
         unknownRedirect: <UnknownRedirect />,
         webAuthnNotSupported: <WebAuthnNotSupported />,
+        sessionAlreadyClaimed: <SessionAlreadyClaimed />,
         unrecoverableFailure: <UnrecoverableFailure />,
         failedDuringSignChallenge: (
             <RetriableFailed
@@ -277,6 +285,26 @@ const WebAuthnNotSupported: React.FC = () => {
     return <Failed message={t("passkeys_not_supported")} />;
 };
 
+const SessionAlreadyClaimed: React.FC = () => {
+    return (
+        <Content>
+            <SessionAlreadyClaimed_>
+                <InfoIcon color="secondary" />
+                <Typography>
+                    {t("passkey_login_already_claimed_session")}
+                </Typography>
+            </SessionAlreadyClaimed_>
+        </Content>
+    );
+};
+
+const SessionAlreadyClaimed_ = styled("div")`
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 2rem;
+`;
+
 const UnrecoverableFailure: React.FC = () => {
     return <Failed message={t("passkey_login_generic_error")} />;
 };
diff --git a/web/apps/accounts/src/services/passkey.ts b/web/apps/accounts/src/services/passkey.ts
index 0fda0c1e00..23dd6a44a6 100644
--- a/web/apps/accounts/src/services/passkey.ts
+++ b/web/apps/accounts/src/services/passkey.ts
@@ -368,6 +368,13 @@ export interface BeginPasskeyAuthenticationResponse {
     };
 }
 
+/**
+ * The passkey session which we are trying to start an authentication ceremony
+ * for has already finished elsewhere.
+ */
+export const passkeySessionAlreadyClaimedErrorMessage =
+    "Passkey session already claimed";
+
 /**
  * Create a authentication ceremony session and return a challenge and a list of
  * public key credentials that can be used to attest that challenge.
@@ -379,6 +386,9 @@ export interface BeginPasskeyAuthenticationResponse {
  *
  * @param passkeySessionID A session created by the requesting app that can be
  * used to initiate a passkey authentication ceremony on the accounts app.
+ *
+ * @throws In addition to arbitrary errors, it throws errors with the message
+ * {@link passkeySessionAlreadyClaimedErrorMessage}.
  */
 export const beginPasskeyAuthentication = async (
     passkeySessionID: string,
@@ -388,7 +398,11 @@ export const beginPasskeyAuthentication = async (
         method: "POST",
         body: JSON.stringify({ sessionID: passkeySessionID }),
     });
-    if (!res.ok) throw new Error(`Failed to fetch ${url}: HTTP ${res.status}`);
+    if (!res.ok) {
+        if (res.status == 409)
+            throw new Error(passkeySessionAlreadyClaimedErrorMessage);
+        throw new Error(`Failed to fetch ${url}: HTTP ${res.status}`);
+    }
 
     // See: [Note: Converting binary data in WebAuthn API payloads]
 
diff --git a/web/packages/accounts/services/passkey.ts b/web/packages/accounts/services/passkey.ts
index 70cd3ae0fa..f16ceeaae9 100644
--- a/web/packages/accounts/services/passkey.ts
+++ b/web/packages/accounts/services/passkey.ts
@@ -209,7 +209,7 @@ const getAccountsToken = async () => {
  * The passkey session whose status we are trying to check has already expired.
  * The user should attempt to login again.
  */
-export const passKeySessionExpiredErrorMessage = "Passkey session has expired";
+export const passkeySessionExpiredErrorMessage = "Passkey session has expired";
 
 /**
  * Check if the user has already authenticated using their passkey for the given
@@ -229,7 +229,7 @@ export const passKeySessionExpiredErrorMessage = "Passkey session has expired";
  * authentication has completed, and `undefined` otherwise.
  *
  * @throws In addition to arbitrary errors, it throws errors with the message
- * {@link passKeySessionExpiredErrorMessage}.
+ * {@link passkeySessionExpiredErrorMessage}.
  */
 export const checkPasskeyVerificationStatus = async (
     sessionID: string,
@@ -241,7 +241,7 @@ export const checkPasskeyVerificationStatus = async (
     });
     if (!res.ok) {
         if (res.status == 404 || res.status == 410)
-            throw new Error(passKeySessionExpiredErrorMessage);
+            throw new Error(passkeySessionExpiredErrorMessage);
         if (res.status == 400) return undefined; /* verification pending */
         throw new Error(`Failed to fetch ${url}: HTTP ${res.status}`);
     }
diff --git a/web/packages/next/locales/en-US/translation.json b/web/packages/next/locales/en-US/translation.json
index 51b63abb2b..c5508e2424 100644
--- a/web/packages/next/locales/en-US/translation.json
+++ b/web/packages/next/locales/en-US/translation.json
@@ -622,6 +622,7 @@
     "passkey_add_failed": "Could not add passkey",
     "passkey_login_failed": "Passkey login failed",
     "passkey_login_invalid_url": "The login URL is invalid.",
+    "passkey_login_already_claimed_session": "This session has already been verified.",
     "passkey_login_generic_error": "An error occurred while logging in with passkey.",
     "passkey_login_credential_hint": "If your passkeys are on a different device, you can open this page on that device to verify.",
     "passkeys_not_supported": "Passkeys are not supported in this browser",
diff --git a/web/packages/shared/components/LoginComponents.tsx b/web/packages/shared/components/LoginComponents.tsx
index 950c6dc4cf..afe12a690d 100644
--- a/web/packages/shared/components/LoginComponents.tsx
+++ b/web/packages/shared/components/LoginComponents.tsx
@@ -3,7 +3,7 @@ import log from "@/next/log";
 import type { BaseAppContextT } from "@/next/types/app";
 import {
     checkPasskeyVerificationStatus,
-    passKeySessionExpiredErrorMessage,
+    passkeySessionExpiredErrorMessage,
     saveCredentialsAndNavigateTo,
 } from "@ente/accounts/services/passkey";
 import EnteButton from "@ente/shared/components/EnteButton";
@@ -108,7 +108,7 @@ export const VerifyingPasskey: React.FC<VerifyingPasskeyProps> = ({
             log.error("Passkey verification status check failed", e);
             setDialogBoxAttributesV2(
                 e instanceof Error &&
-                    e.message == passKeySessionExpiredErrorMessage
+                    e.message == passkeySessionExpiredErrorMessage
                     ? sessionExpiredDialogAttributes(logout)
                     : genericErrorAttributes(),
             );