diff --git a/src/components/AuthenticationFlow/EmailLoginForm.tsx b/src/components/AuthenticationFlow/EmailLoginForm.tsx
index aa2bc9aa8..a348921e8 100644
--- a/src/components/AuthenticationFlow/EmailLoginForm.tsx
+++ b/src/components/AuthenticationFlow/EmailLoginForm.tsx
@@ -3,6 +3,7 @@ import type { FormEvent } from 'react';
 import { useId, useState } from 'react';
 import { httpPost } from '../../lib/http';
 import { TOKEN_COOKIE_NAME, setAuthToken } from '../../lib/jwt';
+import { FIRST_LOGIN_TAG } from './TriggerVerifyAccount';
 
 type EmailLoginFormProps = {
   isDisabled?: boolean;
@@ -38,7 +39,9 @@ export function EmailLoginForm(props: EmailLoginFormProps) {
 
       const currentLocation = window.location.href;
       const url = new URL(currentLocation, window.location.origin);
-      url.searchParams.set('isNewUser', String(response?.isNewUser || false));
+      if (response?.isNewUser) {
+        url.searchParams.set(FIRST_LOGIN_TAG, '1');
+      }
       window.location.href = url.toString();
       return;
     }
diff --git a/src/components/AuthenticationFlow/GitHubButton.tsx b/src/components/AuthenticationFlow/GitHubButton.tsx
index 84ee56f78..2daf89a20 100644
--- a/src/components/AuthenticationFlow/GitHubButton.tsx
+++ b/src/components/AuthenticationFlow/GitHubButton.tsx
@@ -5,6 +5,7 @@ import { TOKEN_COOKIE_NAME, setAuthToken } from '../../lib/jwt';
 import { httpGet } from '../../lib/http';
 import { Spinner } from '../ReactIcons/Spinner.tsx';
 import { triggerUtmRegistration } from '../../lib/browser.ts';
+import { FIRST_LOGIN_TAG } from './TriggerVerifyAccount.tsx';
 
 type GitHubButtonProps = {
   isDisabled?: boolean;
@@ -76,7 +77,9 @@ export function GitHubButton(props: GitHubButtonProps) {
         setAuthToken(response.token);
 
         const url = new URL(redirectUrl, window.location.origin);
-        url.searchParams.set('isNewUser', String(response?.isNewUser || false));
+        if (response?.isNewUser) {
+          url.searchParams.set(FIRST_LOGIN_TAG, '1');
+        }
         window.location.href = url.toString();
       })
       .catch((err) => {
diff --git a/src/components/AuthenticationFlow/GoogleButton.tsx b/src/components/AuthenticationFlow/GoogleButton.tsx
index dae9c4307..a3ef581d4 100644
--- a/src/components/AuthenticationFlow/GoogleButton.tsx
+++ b/src/components/AuthenticationFlow/GoogleButton.tsx
@@ -8,6 +8,7 @@ import {
   getStoredUtmParams,
   triggerUtmRegistration,
 } from '../../lib/browser.ts';
+import { FIRST_LOGIN_TAG } from './TriggerVerifyAccount.tsx';
 
 type GoogleButtonProps = {
   isDisabled?: boolean;
@@ -80,7 +81,9 @@ export function GoogleButton(props: GoogleButtonProps) {
         setAuthToken(response.token);
 
         const url = new URL(redirectUrl, window.location.origin);
-        url.searchParams.set('isNewUser', String(response?.isNewUser || false));
+        if (response?.isNewUser) {
+          url.searchParams.set(FIRST_LOGIN_TAG, '1');
+        }
         window.location.href = url.toString();
       })
       .catch((err) => {
diff --git a/src/components/AuthenticationFlow/LinkedInButton.tsx b/src/components/AuthenticationFlow/LinkedInButton.tsx
index 028ca5cb8..956cc573a 100644
--- a/src/components/AuthenticationFlow/LinkedInButton.tsx
+++ b/src/components/AuthenticationFlow/LinkedInButton.tsx
@@ -5,6 +5,7 @@ import { httpGet } from '../../lib/http';
 import { Spinner } from '../ReactIcons/Spinner.tsx';
 import { LinkedInIcon } from '../ReactIcons/LinkedInIcon.tsx';
 import { triggerUtmRegistration } from '../../lib/browser.ts';
+import { FIRST_LOGIN_TAG } from './TriggerVerifyAccount.tsx';
 
 type LinkedInButtonProps = {
   isDisabled?: boolean;
@@ -75,7 +76,9 @@ export function LinkedInButton(props: LinkedInButtonProps) {
         setAuthToken(response.token);
 
         const url = new URL(redirectUrl, window.location.origin);
-        url.searchParams.set('isNewUser', String(response?.isNewUser || false));
+        if (response?.isNewUser) {
+          url.searchParams.set(FIRST_LOGIN_TAG, '1');
+        }
         window.location.href = url.toString();
       })
       .catch((err) => {
diff --git a/src/components/AuthenticationFlow/TriggerVerifyAccount.tsx b/src/components/AuthenticationFlow/TriggerVerifyAccount.tsx
index 4ef698719..87627a42d 100644
--- a/src/components/AuthenticationFlow/TriggerVerifyAccount.tsx
+++ b/src/components/AuthenticationFlow/TriggerVerifyAccount.tsx
@@ -6,6 +6,8 @@ import { Spinner } from '../ReactIcons/Spinner';
 import { ErrorIcon2 } from '../ReactIcons/ErrorIcon2';
 import { triggerUtmRegistration } from '../../lib/browser.ts';
 
+export const FIRST_LOGIN_TAG = 'fl' as const;
+
 export function TriggerVerifyAccount() {
   const [isLoading, setIsLoading] = useState(true);
   const [error, setError] = useState('');
@@ -32,7 +34,9 @@ export function TriggerVerifyAccount() {
         setAuthToken(response.token);
 
         const url = new URL('/', window.location.origin);
-        url.searchParams.set('isNewUser', String(response?.isNewUser || false));
+        if (response?.isNewUser) {
+          url.searchParams.set(FIRST_LOGIN_TAG, '1');
+        }
         window.location.href = url.toString();
       })
       .catch((err) => {