diff --git a/mafiasi/registration/templates/registration/email_exsts.txt b/mafiasi/registration/templates/registration/email_exsts.txt
new file mode 100644
index 00000000..688f5c4d
--- /dev/null
+++ b/mafiasi/registration/templates/registration/email_exsts.txt
@@ -0,0 +1,17 @@
+{% extends "base_email.html" %}{% load i18n %}{% autoescape off %}
+{% block content_de %}Hallo,
+du hast versucht, einen Account zu erstellen, den es schon gibt. Falls du dein Passwort vergessen hast, kannst du es hier zurücksetzen:
+{{ password_reset_url }}
+Dein Nutzername ist {{ username }}.
+
+Viele Grüße,
+Deine Server-AG
+{% endblock %}
+{% block content_en %}Hello,
+you tried to create an account that already exists. If you forgot your password, you can reset it here:
+{{ password_reset_url }}
+Your username is {{ username }}.
+
+Best regards,
+Your Server-AG
+{% endblock %}{% endautoescape %}
diff --git a/mafiasi/registration/views.py b/mafiasi/registration/views.py
index fadad03d..2ebb927d 100644
--- a/mafiasi/registration/views.py
+++ b/mafiasi/registration/views.py
@@ -71,6 +71,10 @@ def request_account(request):
                             slug="employee", defaults={"name": "Employee"}
                         )
 
+                username = _get_username({"account": account, "domain": domain}, yeargroup)
+                if Mafiasi.objects.filter(username=username).exists():
+                    return _send_email_exists(request, username)
+
                 return _finish_account_request(
                     request,
                     {
@@ -130,6 +134,10 @@ def additional_info(request):
     if form.is_valid():
         account = form.cleaned_data["account"]
         domain = form.cleaned_data["domain"]
+        username = _get_username({"account": account, "domain": domain}, form.cleaned_data["yeargroup"])
+        if Mafiasi.objects.filter(username=username).exists():
+            return _send_email_exists(request, username)
+
         return _finish_account_request(
             request,
             {
@@ -148,7 +156,7 @@ def request_successful(request):
     return TemplateResponse(request, "registration/request_successful.html")
 
 
-def _create_username(info, yeargroup):
+def _get_username(info, yeargroup):
     if info["domain"] != settings.PRIMARY_DOMAIN:
         return "{}.{}".format(info["account"], settings.REGISTER_DOMAIN_MAPPING[info["domain"]])
     elif info["account"][0].isdigit():
@@ -169,10 +177,10 @@ def create_account(request, info_token):
         return TemplateResponse(request, "registration/token_invalid.html")
 
     yeargroup = Yeargroup.objects.get(pk=info["yeargroup_pk"])
-    username = _create_username(info, yeargroup)
+    username = _get_username(info, yeargroup)
 
     if Mafiasi.objects.filter(username=username).exists():
-        return redirect("simple_openid_connect.login")
+        return redirect(reverse("simple_openid_connect:login"))
 
     if request.method == "POST":
         form = PasswordForm(request.POST)
@@ -306,6 +314,20 @@ def _finish_account_request(request, info):
     )
 
 
+def _send_email_exists(request, username):
+    email = Mafiasi.objects.get(username=username).real_email
+    email_content = render_to_string(
+        "registration/email_exists.txt",
+        {
+            "username": username,
+            "password_reset_url": settings.PASSWORD_RESET_URL,
+        },
+    )
+    return _send_mail_or_error_page(
+        _("Account exists at %s" % settings.PROJECT_NAME), email_content, email, request, None
+    )
+
+
 def _send_mail_or_error_page(subject, content, address, request, email_shown):
     try:
         send_mail(subject, content, None, [address])
diff --git a/mafiasi/settings.py b/mafiasi/settings.py
index a3ef7fe2..4c12413d 100644
--- a/mafiasi/settings.py
+++ b/mafiasi/settings.py
@@ -30,6 +30,10 @@
 KEYCLOAK_ACCOUNT_CONSOLE_URL = env.str(
     "MAFIASI_KEYCLOAK_ACCOUNT_CONSOLE_URL", default="https://identity.mafiasi.de/realms/mafiasi/account"
 )
+PASSWORD_RESET_URL = env.str(
+    "MAFIASI_PASSWORD_RESET_URL",
+    default="https://identity.mafiasi.de/realms/mafiasi/login-actions/reset-credentials?client_id=mafiasi-dashboard",
+)
 
 OPENID_SYNC_SUPERUSER = env.bool("MAFIASI_OPENID_SYNC_SUPERUSER", default=True)
 if OPENID_SYNC_SUPERUSER: