diff --git a/src/Handler/Utils/Avs.hs b/src/Handler/Utils/Avs.hs
index eb7d42d8d..e6dbf4943 100644
--- a/src/Handler/Utils/Avs.hs
+++ b/src/Handler/Utils/Avs.hs
@@ -357,12 +357,12 @@ updateAvsUserByADC newAvsDataContact@(AvsDataContact apid newAvsPersonInfo newAv
                               (mkCheckUpdate CU_API_UserLdapPrimaryKey)
                               [mkCheckUpdate CU_API_UserCompanyPersonalNumber]
         let per_ups = mapMaybe (mkUpdate' usr newAvsPersonInfo oldAvsPersonInfo . mkCheckUpdate)
-                      [ CU_API_UserFirstName            
-                      , CU_API_UserSurname              
-                      , CU_API_UserDisplayName          
-                      , CU_API_UserBirthday             
-                      , CU_API_UserMobile               
-                      , CU_API_UserMatrikelnummer       
+                      [ CU_API_UserFirstName
+                      , CU_API_UserSurname          
+                      , CU_API_UserDisplayName
+                      , CU_API_UserBirthday
+                      , CU_API_UserMobile
+                      , CU_API_UserMatrikelnummer
                       -- , CU_API_UserCompanyPersonalNumber -- needs special treatment, see ldap_ups above
                       ]
             eml_up =  mkUpdate usr newAvsDataContact oldAvsDataContact $ mkCheckUpdate CU_ADC_UserDisplayEmail                            -- Email updates erfolgen nur, wenn identisch. Für Firmen-Email leer lassen.
diff --git a/src/Model/Types/Avs.hs b/src/Model/Types/Avs.hs
index 5e6abd2ed..ef9752f0f 100644
--- a/src/Model/Types/Avs.hs
+++ b/src/Model/Types/Avs.hs
@@ -31,7 +31,7 @@ import Data.Aeson
 import Data.Aeson.Types as Aeson
 
 import Utils.Postal (validPostAddressText)
-import Utils.Mail (pickValidEmail)
+import Utils.Mail (pickValidEmail, canonicalPhone)
 
 
 {-
@@ -557,14 +557,14 @@ _avsInfoDisplayName = lens g s
 
 instance FromJSON AvsPersonInfo where
   parseJSON = withObject "AvsPersonInfo" $ \o -> AvsPersonInfo
-    <$> o .:   "PersonsNo"                                      -- NOTE: PersonsNo, not PersonNo as elsewhere
-    <*> o .:   "FirstName"
-    <*> o .:   "LastName"
-    <*> o .:   "RampLicence"
-    <*> o .:?  "DateOfBirth"
-    <*> o .:?! "PersonEMail"
-    <*> o .:?! "PersonMobilePhoneNo"
-    <*> o .:?! "InternalPersonalNo"
+    <$>  o .:   "PersonsNo"                                      -- NOTE: PersonsNo, not PersonNo as elsewhere
+    <*>  o .:   "FirstName"
+    <*>  o .:   "LastName"
+    <*>  o .:   "RampLicence"
+    <*>  o .:?  "DateOfBirth"
+    <*>  o .:?! "PersonEMail"
+    <*> (o .:?! "PersonMobilePhoneNo" <&> fmap canonicalPhone)
+    <*>  o .:?! "InternalPersonalNo"
 
 
 instance ToJSON AvsPersonInfo where
diff --git a/src/Utils/Mail.hs b/src/Utils/Mail.hs
index a59498e39..5085efcf6 100644
--- a/src/Utils/Mail.hs
+++ b/src/Utils/Mail.hs
@@ -58,7 +58,39 @@ pickValidUserEmail x y
 
 -- | returns first valid email address or none if none are valid
 pickValidUserEmail' :: CI Text -> CI Text -> Maybe (CI Text)
-pickValidUserEmail' x y 
+pickValidUserEmail' x y
   | validEmail' x = Just x
   | validEmail' y = Just y
-  | otherwise     = Nothing      
\ No newline at end of file
+  | otherwise     = Nothing
+
+
+--------------------
+-- Telephone Utils
+
+-- | normalize phone numbers
+canonicalPhone :: Text -> Text
+canonicalPhone pn
+  | Just pn01 <- Text.stripPrefix "01" pn
+    = german_mobile pn01 
+  | Just pn01 <- Text.stripPrefix "+491" pn
+    = german_mobile pn01
+  | Just pn00 <- Text.stripPrefix "00" pn
+    = Text.cons '+' $ Text.map repl_nondigit pn00
+  | Just ('0', pn0) <- Text.uncons pn
+  , Just (snr,  _ ) <- Text.uncons pn0
+  , snr /= '0'
+  , Char.isDigit snr
+    = "+49 " <> Text.map repl_nondigit pn0
+  | otherwise
+    = Text.map repl_nondigit pn
+  where
+    german_mobile :: Text -> Text
+    german_mobile wpx =
+      let (area,endnr) = Text.splitAt 2 $ Text.filter Char.isDigit wpx
+      in "+49 1" <> area <> Text.cons ' ' endnr
+
+    repl_nondigit :: Char -> Char
+    repl_nondigit c
+      | Char.isDigit c = c
+      | c == '+'       = '+'
+      | otherwise      = ' '