diff --git a/taiga/auth/services.py b/taiga/auth/services.py
index 70da5281..777311aa 100644
--- a/taiga/auth/services.py
+++ b/taiga/auth/services.py
@@ -141,7 +141,7 @@ def private_register_for_existing_user(token:str, username:str, password:str):
         membership.user = user
         membership.save(update_fields=["user"])
     except IntegrityError:
-        raise exc.IntegrityError(_("Membership with user is already exists."))
+        raise exc.IntegrityError(_("This user is already a member of the project."))
 
     send_register_email(user)
     return user
diff --git a/taiga/locale/ca/LC_MESSAGES/django.po b/taiga/locale/ca/LC_MESSAGES/django.po
index 063a8865..4231447c 100644
--- a/taiga/locale/ca/LC_MESSAGES/django.po
+++ b/taiga/locale/ca/LC_MESSAGES/django.po
@@ -9,8 +9,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-02 13:35+0000\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
 "Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Catalan (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/ca/)\n"
@@ -58,8 +58,8 @@ msgid "User is already registered."
 msgstr "Aquest usuari ja està registrat"
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Aquest usuari ja es membre"
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/de/LC_MESSAGES/django.po b/taiga/locale/de/LC_MESSAGES/django.po
index 92c3539e..e50e4743 100644
--- a/taiga/locale/de/LC_MESSAGES/django.po
+++ b/taiga/locale/de/LC_MESSAGES/django.po
@@ -17,9 +17,9 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-11 09:45+0000\n"
-"Last-Translator: Guido Brand\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
+"Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: German (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/de/)\n"
 "MIME-Version: 1.0\n"
@@ -68,8 +68,8 @@ msgid "User is already registered."
 msgstr "Der Benutzer ist schon registriert."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Der Benutzer für diese Mitgliedschaft existiert bereits."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/en/LC_MESSAGES/django.po b/taiga/locale/en/LC_MESSAGES/django.po
index f54add46..b6d0fae0 100644
--- a/taiga/locale/en/LC_MESSAGES/django.po
+++ b/taiga/locale/en/LC_MESSAGES/django.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
 "PO-Revision-Date: 2015-03-25 20:09+0100\n"
 "Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Taiga Dev Team <support@taiga.io>\n"
@@ -54,7 +54,7 @@ msgid "User is already registered."
 msgstr ""
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
+msgid "This user is already a member of the project."
 msgstr ""
 
 #: taiga/auth/services.py:170
diff --git a/taiga/locale/es/LC_MESSAGES/django.po b/taiga/locale/es/LC_MESSAGES/django.po
index c04a0dd3..45427d54 100644
--- a/taiga/locale/es/LC_MESSAGES/django.po
+++ b/taiga/locale/es/LC_MESSAGES/django.po
@@ -13,9 +13,9 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-02 21:24+0000\n"
-"Last-Translator: Jesus Marin <contacto@jesusmg.org>\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
+"Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Spanish (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/es/)\n"
 "MIME-Version: 1.0\n"
@@ -62,8 +62,8 @@ msgid "User is already registered."
 msgstr "Este usuario ya está registrado."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Ya existe una membresía asociada a este usuario."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/fi/LC_MESSAGES/django.po b/taiga/locale/fi/LC_MESSAGES/django.po
index ebc557e3..3c5e2065 100644
--- a/taiga/locale/fi/LC_MESSAGES/django.po
+++ b/taiga/locale/fi/LC_MESSAGES/django.po
@@ -9,8 +9,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-02 08:25+0000\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
 "Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Finnish (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/fi/)\n"
@@ -59,8 +59,8 @@ msgid "User is already registered."
 msgstr "Käyttäjä on jo rekisteröitynyt."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Jäsenyys on jo olemassa."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/fr/LC_MESSAGES/django.po b/taiga/locale/fr/LC_MESSAGES/django.po
index 43a5dc7f..71c9fa5a 100644
--- a/taiga/locale/fr/LC_MESSAGES/django.po
+++ b/taiga/locale/fr/LC_MESSAGES/django.po
@@ -18,9 +18,9 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-17 20:48+0000\n"
-"Last-Translator: Regis TEDONE <regis.tedone@gmail.com>\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
+"Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: French (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/fr/)\n"
 "MIME-Version: 1.0\n"
@@ -68,8 +68,8 @@ msgid "User is already registered."
 msgstr "Cet utilisateur est déjà inscrit."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Cet utilisateur est déjà membre."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/it/LC_MESSAGES/django.po b/taiga/locale/it/LC_MESSAGES/django.po
index be121f5c..56959497 100644
--- a/taiga/locale/it/LC_MESSAGES/django.po
+++ b/taiga/locale/it/LC_MESSAGES/django.po
@@ -13,9 +13,9 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-10 14:10+0000\n"
-"Last-Translator: Andrea Raimondi <raimondi.and@gmail.com>\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
+"Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Italian (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/it/)\n"
 "MIME-Version: 1.0\n"
@@ -64,8 +64,8 @@ msgid "User is already registered."
 msgstr "L'Utente è già registrato."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "L'utente risulta già associato."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/nl/LC_MESSAGES/django.po b/taiga/locale/nl/LC_MESSAGES/django.po
index a9f6772b..b3c24261 100644
--- a/taiga/locale/nl/LC_MESSAGES/django.po
+++ b/taiga/locale/nl/LC_MESSAGES/django.po
@@ -9,8 +9,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-02 13:41+0000\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
 "Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Dutch (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/nl/)\n"
@@ -58,8 +58,8 @@ msgid "User is already registered."
 msgstr "Gebruiker is al geregistreerd."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Lidmaatschap met gebruiker bestaat al."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/pl/LC_MESSAGES/django.po b/taiga/locale/pl/LC_MESSAGES/django.po
index 52b696ff..d2e1e8f9 100644
--- a/taiga/locale/pl/LC_MESSAGES/django.po
+++ b/taiga/locale/pl/LC_MESSAGES/django.po
@@ -10,8 +10,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-02 08:25+0000\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
 "Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Polish (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/pl/)\n"
@@ -60,8 +60,8 @@ msgid "User is already registered."
 msgstr "Użytkownik już zarejestrowany"
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Członkowstwo z użytkownikiem już istnieje."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/pt_BR/LC_MESSAGES/django.po b/taiga/locale/pt_BR/LC_MESSAGES/django.po
index 21b3b2b5..e3fca96d 100644
--- a/taiga/locale/pt_BR/LC_MESSAGES/django.po
+++ b/taiga/locale/pt_BR/LC_MESSAGES/django.po
@@ -18,8 +18,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-02 08:25+0000\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
 "Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Portuguese (Brazil) (http://www.transifex.com/taiga-agile-llc/"
 "taiga-back/language/pt_BR/)\n"
@@ -67,8 +67,8 @@ msgid "User is already registered."
 msgstr "Este usuário já está registrado."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Esse usuário já é membro."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/ru/LC_MESSAGES/django.po b/taiga/locale/ru/LC_MESSAGES/django.po
index 451c5c66..b3c236d1 100644
--- a/taiga/locale/ru/LC_MESSAGES/django.po
+++ b/taiga/locale/ru/LC_MESSAGES/django.po
@@ -12,9 +12,9 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-07 12:59+0000\n"
-"Last-Translator: Dmitriy Volkov <wldhx+reg+transifex@wldhx.me>\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
+"Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Russian (http://www.transifex.com/taiga-agile-llc/taiga-back/"
 "language/ru/)\n"
 "MIME-Version: 1.0\n"
@@ -63,8 +63,8 @@ msgid "User is already registered."
 msgstr "Пользователь уже зарегистрирован."
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "Членство с этим пользователем уже существует."
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."
diff --git a/taiga/locale/zh-Hant/LC_MESSAGES/django.po b/taiga/locale/zh-Hant/LC_MESSAGES/django.po
index e871dced..8263e82c 100644
--- a/taiga/locale/zh-Hant/LC_MESSAGES/django.po
+++ b/taiga/locale/zh-Hant/LC_MESSAGES/django.po
@@ -11,8 +11,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: taiga-back\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2016-01-05 11:11+0100\n"
-"PO-Revision-Date: 2015-11-02 08:25+0000\n"
+"POT-Creation-Date: 2016-01-07 11:11+0100\n"
+"PO-Revision-Date: 2016-01-07 10:12+0000\n"
 "Last-Translator: Taiga Dev Team <support@taiga.io>\n"
 "Language-Team: Chinese Traditional (http://www.transifex.com/taiga-agile-llc/"
 "taiga-back/language/zh-Hant/)\n"
@@ -60,8 +60,8 @@ msgid "User is already registered."
 msgstr "使用者已被註冊。"
 
 #: taiga/auth/services.py:144
-msgid "Membership with user is already exists."
-msgstr "使用者的成員資格已存在。"
+msgid "This user is already a member of the project."
+msgstr ""
 
 #: taiga/auth/services.py:170
 msgid "Error on creating new user."