diff --git a/frontend/src/utils/exam-correct/exam-correct.js b/frontend/src/utils/exam-correct/exam-correct.js
index 5a7ffc9ca..3c9a1c9f0 100644
--- a/frontend/src/utils/exam-correct/exam-correct.js
+++ b/frontend/src/utils/exam-correct/exam-correct.js
@@ -47,6 +47,7 @@ export class ExamCorrect {
   _userInputStatus;
   _userInputCandidates;
   _partInputs;
+  _partDeleteBoxes;
 
   _dateFormat;
   _cIndices;
@@ -75,6 +76,7 @@ export class ExamCorrect {
     this._userInputStatus = document.getElementById(EXAM_CORRECT_USER_INPUT_STATUS_ID);
     this._userInputCandidates = document.getElementById(EXAM_CORRECT_USER_INPUT_CANDIDATES_ID);
     this._partInputs = [...this._element.querySelectorAll(`input[${EXAM_CORRECT_PART_INPUT_ATTR}]`)];
+    this._partDeleteBoxes = [...this._element.querySelectorAll('input.uw-exam-correct--delete-exam-part')];
 
     if (this._sendBtn)
       this._sendBtn.addEventListener('click', this._sendCorrectionHandler.bind(this));
@@ -84,6 +86,10 @@ export class ExamCorrect {
       this._userInput.addEventListener('focusout', this._validateUserInput.bind(this));
     else throw new Error('ExamCorrect utility could not detect user input!');
 
+    for (let deleteBox of this._partDeleteBoxes) {
+      deleteBox.addEventListener('change', (() => { this._updatePartDeleteDisabled(deleteBox); }).bind(this));
+    }
+
     if (!this._userInputStatus) {
       throw new Error('ExamCorrect utility could not detect user input status element!');
     }
@@ -93,7 +99,7 @@ export class ExamCorrect {
     }
 
     // TODO get date format by post request
-    this._dateFormat = 'YYYY-MM-DD HH:mm:ss';
+    this._dateFormat = 'DD.MM.YYYY HH:mm:ss';
 
     this._cIndices = new Map(
       [...this._element.querySelectorAll('[uw-exam-correct-header]')]
@@ -116,6 +122,14 @@ export class ExamCorrect {
     // TODO destroy handlers on user input candidate elements
   }
 
+  _updatePartDeleteDisabled(deleteBox) {
+    const partInput = deleteBox.parentElement.querySelector(`input[${EXAM_CORRECT_PART_INPUT_ATTR}]`);
+    if (!partInput)
+      return;
+
+    partInput.disabled = deleteBox.checked;
+  }
+
   _validateUserInput() {
     (!this._userInput.value) ? this._userInput.classList.add('no-value') : this._userInput.classList.remove('no-value');
 
@@ -176,11 +190,17 @@ export class ExamCorrect {
 
     const results = {};
     for (const input of this._partInputs) {
-      if (input.reportValidity && !input.reportValidity()) {
+      if (input.disabled) {
+        const partKey = input.getAttribute(EXAM_CORRECT_PART_INPUT_ATTR);
+        if (!partKey) {
+          console.error('Error while parsing results: Could not detect exam part key attribute');
+          return;
+        }
+        results[partKey] = null;
+      } else if (input.reportValidity && !input.reportValidity()) {
         input.focus();
         return;
-      }
-      if (input.value) {
+      } else if (input.value) {
         const partKey = input.getAttribute(EXAM_CORRECT_PART_INPUT_ATTR);
         if (!partKey) {
           console.error('Error while parsing results: Could not detect exam part key attribute');
@@ -189,24 +209,25 @@ export class ExamCorrect {
         results[partKey] = parseFloat(input.value);
       }
     }
+    console.log('results', results);
 
-    const result = this._resultSelect.value !== 'none' && this._resultSelect.value;
+    const result = this._resultSelect && this._resultSelect.value !== 'none' && this._resultSelect.value;
 
     // abort send if there are no results (after validation)
-    if (Object.keys(results).length <= 0) return;
+    if (Object.keys(results).length <= 0 && !result) return;
 
     const rowInfo = {
       users: [user],
       results: results,
+      result: result === 'delete' ? null : result,
       status: STATUS.LOADING,
     };
-    if (results) rowInfo.results = results;
-    if (result) rowInfo.result = result === 'delete' ? null : result;
     this._addRow(rowInfo);
 
     // clear inputs on validation success
     this._clearUserInput();
     this._partInputs.forEach(clearInput);
+    this._partDeleteBoxes.forEach(box => { box.checked = false; this._updatePartDeleteDisabled(box); });
 
     const body = {
       user: userId || user,
@@ -305,39 +326,38 @@ export class ExamCorrect {
             case 'success':
               status = STATUS.SUCCESS;
               if (response.user) {
-                userElem.setAttribute(EXAM_CORRECT_USER_ATTR, response.user.id);
-                userElem.innerHTML = userToHTML(response.user);
                 const timeElem = row.cells.item(0);
                 timeElem.innerHTML = moment(response.time).format(this._dateFormat);
                 timeElem.classList.remove('exam-correct--local-time');
                 newEntry.users = [response.user];
                 newEntry.results = response.results;
                 newEntry.result = response.grade;
+              } else {
+                console.error('Invalid response');
+                return;
               }
               // TODO set edit button visibility
               break;
             case 'ambiguous':
               // TODO set edit button visibility
               status = STATUS.AMBIGUOUS;
-              if (response.users) {
-                userElem = this._showUserList(row, response.users, results);
-                newEntry.users = response.users;
-                newEntry.results = results.partResults;
-                newEntry.result = results.result;
-              }
+              newEntry.users = response.users;
+              newEntry.results = typeof results === 'undefined' ? {} : results;
+              newEntry.result = typeof result === 'undefined' ? undefined : result; // eslint-disable-line no-undef
               newEntry.message = response.message || null;
               break;
             case 'failure':
               status = STATUS.FAILURE;
               newEntry.users = (response.user && [response.user]) || null;
-              newEntry.results = results;
+              newEntry.results = typeof results === 'undefined' ? {} : results;
               newEntry.message = response.message || null;
-              newEntry.result = results.result;
+              newEntry.result = typeof result === 'undefined' ? undefined : result; // eslint-disable-line no-undef
               break;
             default:
               // TODO show tooltip with 'invalid response'
               // TODO set edit button visibility
               console.error('Invalid response');
+              return;
           }
           row.querySelectorAll('.fa-spin').forEach((elem) => {
             setStatus(elem, status);
@@ -359,19 +379,23 @@ export class ExamCorrect {
             statusCell.appendChild(messageElem);
           }
 
-          const userCell = row.querySelector('.uw-exam-correct--user-cell');
-          if (userCell && newEntry.users && newEntry.users.length === 1) {
+          if (userElem && newEntry.users && newEntry.users.length === 1) {
             const user = newEntry.users[0];
-            userCell.innerHTML = userToHTML(user);
-            userCell.setAttribute(EXAM_CORRECT_USER_ATTR, user);
-          } else if (userCell && newEntry.users) {
-            row.replaceChild(userCell, this._showUserList(row, newEntry.users, request.results));
+            userElem.innerHTML = userToHTML(user);
+            userElem.setAttribute(EXAM_CORRECT_USER_ATTR, user.id || user);
+          } else if (userElem && newEntry.users) {
+            row.replaceChild(userElem, this._showUserList(row, newEntry.users, { partResults: request.results, result: request.grade } ));
           }
 
           for (let [k, v] of Object.entries(newEntry.results)) {
             const resultCell = row.cells.item(this._cIndices.get(k));
-            if (v.result)
+            if (v === null) {
+              resultCell.innerHTML = '<i class="fas fa-fw fa-trash"></i>';
+              resultCell.classList.remove('exam-correct--result-unconfirmed');
+            } else if (v && v.result) {
               resultCell.innerHTML = v.result;
+              resultCell.classList.remove('exam-correct--result-unconfirmed');
+            }
           }
 
           savedEntries.push(newEntry);
@@ -429,9 +453,9 @@ export class ExamCorrect {
 
     const body = {
       user: listItem.getAttribute(EXAM_CORRECT_USER_ATTR),
-      results: results.partResults,
-      grade: results.result,
     };
+    if (results.partResults) body.results = results.partResults;
+    if (results.result || results.result === null) body.grade = results.result;
 
     this._app.httpClient.post({
       url: EXAM_CORRECT_URL_POST,
@@ -478,8 +502,13 @@ export class ExamCorrect {
         console.error('Could not determine cell index from part key!');
       } else {
         const partCell = document.createElement('TD');
-        partCell.innerHTML = partResult;
-        partCell.classList.add('uw-exam-correct--part-cell');
+
+        if (partResult === null) {
+          partCell.innerHTML = '<i class="fas fa-fw fa-trash"></i>';
+        } else {
+          partCell.innerHTML = partResult;
+        }
+        partCell.classList.add('uw-exam-correct--part-cell', 'exam-correct--result-unconfirmed');
         cells.set(cellIndex, partCell);
       }
     }
diff --git a/frontend/src/utils/exam-correct/exam-correct.sass b/frontend/src/utils/exam-correct/exam-correct.sass
index 9b5d3658a..f0554a692 100644
--- a/frontend/src/utils/exam-correct/exam-correct.sass
+++ b/frontend/src/utils/exam-correct/exam-correct.sass
@@ -12,7 +12,7 @@ table[uw-exam-correct]
     min-width: 200px
 
   th.uw-exam-correct--part-cell, td.uw-exam-correct--part-cell
-    width: min-content
+    width: 115px
     text-align: center
     white-space: nowrap
     
@@ -24,12 +24,16 @@ table[uw-exam-correct]
       opacity: .5
       cursor: pointer
       margin-left: 5px
-    .uw-exam-correct--delete-exam-part ~ .fa-trash:hover
-      opacity: 1
+
+      &:hover
+        opacity: 1
     .uw-exam-correct--delete-exam-part:checked ~ .fa-trash
       opacity: 1
       color: var(--color-error)
 
+      &:hover
+        color: var(--color-error-dark)
+
   td#uw-exam-correct__result
     width: min-content
     select
@@ -63,7 +67,6 @@ table[uw-exam-correct]
   border: 2px solid var(--color-error)
 
 [uw-exam-correct] tbody ul
-  list-style: none
   li
     cursor: pointer
     text-decoration: underline
@@ -73,9 +76,11 @@ table[uw-exam-correct]
     width: calc(100% - 18em/14 - #{$exam-correct--input-status-margin})
   i
     margin-left: $exam-correct--input-status-margin
+  ul
+    margin-top: 7px
 
-.exam-correct--local-time
-  color: var(--color-fontsec)
+.exam-correct--local-time, .exam-correct--result-unconfirmed
+  opacity: .5
   font-style: italic
 
 .exam-correct--success
diff --git a/messages/uniworx/de-de-formal.msg b/messages/uniworx/de-de-formal.msg
index e79cff87f..3fcff0514 100644
--- a/messages/uniworx/de-de-formal.msg
+++ b/messages/uniworx/de-de-formal.msg
@@ -413,6 +413,7 @@ UnauthorizedAllocationLecturer: Sie sind nicht als Veranstalter für eine Verans
 UnauthorizedCorrector: Sie sind nicht als Korrektor für diese Veranstaltung eingetragen.
 UnauthorizedSheetCorrector: Sie sind nicht als Korrektor für dieses Übungsblatt eingetragen.
 UnauthorizedExamCorrector: Sie sind nicht als Korrektor für diese Prüfung eingetragen.
+UnauthorizedExamCorrectorGrade: Sie haben nicht die Berechtigung für diese Prüfung Gesamtergebnisse einzutragen.
 UnauthorizedCorrectorAny: Sie sind nicht als Korrektor für eine Veranstaltung eingetragen.
 UnauthorizedRegistered: Sie sind nicht als Teilnehmer für diese Veranstaltung registriert.
 UnauthorizedAllocationRegistered: Sie sind nicht als Teilnehmer für diese Zentralanmeldung registriert.
diff --git a/messages/uniworx/en-eu.msg b/messages/uniworx/en-eu.msg
index 8f829c850..e0fa571fd 100644
--- a/messages/uniworx/en-eu.msg
+++ b/messages/uniworx/en-eu.msg
@@ -411,6 +411,7 @@ UnauthorizedAllocationLecturer: You are no administrator for any of the courses
 UnauthorizedCorrector: You are no sheet corrector for this course.
 UnauthorizedSheetCorrector: You are no corrector for this sheet.
 UnauthorizedExamCorrector: You are no corrector for this exam.
+UnauthorizedExamCorrectorGrade: You may not enter overall exam achievements for this exam.
 UnauthorizedCorrectorAny: You are no corrector for any course.
 UnauthorizedRegistered: You are no participant in this course.
 UnauthorizedAllocationRegistered: You are no participant in this central allocation.
diff --git a/src/Handler/Exam/Correct.hs b/src/Handler/Exam/Correct.hs
index 35736c4c8..34633609b 100644
--- a/src/Handler/Exam/Correct.hs
+++ b/src/Handler/Exam/Correct.hs
@@ -10,10 +10,13 @@ import qualified Data.Aeson as JSON
 
 import qualified Database.Esqueleto as E
 import qualified Database.Esqueleto.Utils as E
+import Database.Persist.Sql (transactionUndo)
 
 import Handler.Utils
 import Handler.Utils.Exam (fetchExam)
 
+import qualified Data.HashMap.Strict as HashMap
+
 
 data CorrectInterfaceUser
   = CorrectInterfaceUser
@@ -30,7 +33,7 @@ data CorrectInterfaceResponse
   = CorrectInterfaceResponseSuccess
     { cirsUser       :: CorrectInterfaceUser
     , cirsResults    :: Map ExamPartNumber (Maybe ExamResultPoints)
-    , cirsGrade      :: Maybe ExamResultPassedGrade
+    , cirsGrade      :: Maybe (Maybe ExamResultPassedGrade)
     , cirsTime       :: UTCTime
     }
   | CorrectInterfaceResponseAmbiguous
@@ -44,17 +47,18 @@ data CorrectInterfaceResponse
   | CorrectInterfaceResponseNoOp
     { cirnUsers      :: Set CorrectInterfaceUser
     }
-deriveJSON defaultOptions
+deriveToJSON defaultOptions
   { constructorTagModifier = camelToPathPiece' 3
   , fieldLabelModifier     = camelToPathPiece' 1
   , sumEncoding            = TaggedObject "status" "results"
+  , omitNothingFields      = True
   } ''CorrectInterfaceResponse
 
 data CorrectInterfaceRequest
   = CorrectInterfaceRequest
     { ciqUser        :: Either Text (CryptoID UUID (Key User))
     , ciqResults     :: Maybe (NonNull (Map ExamPartNumber (Maybe Points)))
-    , ciqGrade       :: Maybe ExamResultPassedGrade
+    , ciqGrade       :: Maybe (Maybe ExamResultPassedGrade)
     }
 
 instance FromJSON CorrectInterfaceRequest where
@@ -62,7 +66,11 @@ instance FromJSON CorrectInterfaceRequest where
     ciqUser <- Right <$> o JSON..: "user" <|> Left <$> o JSON..: "user"
     results <- o JSON..:? "results"
     ciqResults <- for results $ maybe (fail "Results may not be nullable") return . fromNullable
-    ciqGrade <- o JSON..:? "grade"
+    ciqGrade <- if
+      | "grade" `HashMap.member` o
+        -> Just <$> o JSON..: "grade"
+      | otherwise
+        -> pure Nothing
     return CorrectInterfaceRequest{..}
 
 
@@ -104,7 +112,9 @@ postECorrectR tid ssh csh examn = do
 
   CorrectInterfaceRequest{..} <- requireCheckJsonBody
 
-  response <- exceptT return return . hoist runDB $ do
+  let mayEditResults = False
+  
+  response <- runDB . exceptT (<$ transactionUndo) return $ do
     Entity eId Exam{..} <- lift $ fetchExam tid ssh csh examn
     euid <- traverse decrypt ciqUser
 
@@ -192,20 +202,22 @@ postECorrectR tid ssh csh examn = do
               | otherwise -> return Nothing
             | otherwise -> return mempty
 
-        newExamResult <- lift $ do
+        newExamResult <- for ciqGrade $ \ciqGrade' -> lift $ do
+          unless mayEditResults $
+            permissionDeniedI MsgUnauthorizedExamCorrectorGrade
           mOldResult <- getBy $ UniqueExamResult eId uid
           if
-            | Just (Entity oldId _) <- mOldResult, is _Nothing ciqGrade -> do
-              delete oldId
-              audit $ TransactionExamResultDeleted eId uid
-              return Nothing
-            | Just result <- ciqGrade -> let
+            | Just (Entity oldId _) <- mOldResult, is _Nothing ciqGrade' -> do
+                delete oldId
+                audit $ TransactionExamResultDeleted eId uid
+                return Nothing
+            | Just result <- ciqGrade' -> let
                 mOld = view passedGrade . examResultResult . entityVal <$> mOldResult
                 resultGrade = review passedGrade result
                 passedGrade :: Iso' ExamResultGrade ExamResultPassedGrade
                 passedGrade = iso (fmap $ bool (Left . view passingGrade) Right examShowGrades) (fmap $ either (review passingGrade) id)
               in if
-                | ciqGrade /= mOld -> do
+                | ciqGrade' /= mOld -> do
                   newResult <- upsert ExamResult
                     { examResultExam        =  eId
                     , examResultUser        =  uid