diff --git a/src/main/java/edu/harvard/iq/dataverse/EditDatafilesPage.java b/src/main/java/edu/harvard/iq/dataverse/EditDatafilesPage.java
index 56831834c31..850ae32ec8e 100644
--- a/src/main/java/edu/harvard/iq/dataverse/EditDatafilesPage.java
+++ b/src/main/java/edu/harvard/iq/dataverse/EditDatafilesPage.java
@@ -356,11 +356,13 @@ public boolean isUnlimitedUploadFileSize() {
     }
     
     public Long getMaxTotalUploadSizeInBytes() {
-        return maxTotalUploadSizeInBytes;
+        return uploadSessionQuota == null
+                ? maxTotalUploadSizeInBytes
+                : uploadSessionQuota.getRemainingQuotaInBytes();
     }
     
     public String getHumanMaxTotalUploadSizeInBytes() {
-        return FileSizeChecker.bytesToHumanReadable(maxTotalUploadSizeInBytes);
+        return FileSizeChecker.bytesToHumanReadable(getMaxTotalUploadSizeInBytes());
     }
     
     public boolean isStorageQuotaEnforced() {
@@ -981,6 +983,8 @@ private void deleteFiles(List<FileMetadata> filesForDelete) {
                 // removing it from the fileMetadatas lists (above), we also remove it from
                 // the newFiles list and the dataset's files, so it never gets saved.
 
+                releaseUploadQuota(markedForDelete.getDataFile());
+
                 FileMetadataUtil.removeDataFileFromList(dataset.getFiles(), markedForDelete.getDataFile());
                 FileMetadataUtil.removeDataFileFromList(newFiles, markedForDelete.getDataFile());
                 FileUtil.deleteTempFile(markedForDelete.getDataFile(), dataset, ingestService);
@@ -1011,6 +1015,13 @@ private void deleteFiles(List<FileMetadata> filesForDelete) {
         }
     }
 
+    private void releaseUploadQuota(DataFile dataFile) {
+        if (uploadSessionQuota != null && dataFile.getFilesize() > 0) {
+            uploadSessionQuota.setTotalUsageInBytes(Math.max(0L,
+                    uploadSessionQuota.getTotalUsageInBytes() - dataFile.getFilesize()));
+        }
+    }
+
     /**
      * Save for File Replace operations
      *
@@ -2190,6 +2201,22 @@ public void handleExternalUpload() {
                     Optional.ofNullable(editDataFilesPageHelper.getHtmlErrorMessage(createDataFilesResult)).ifPresent(errorMessage -> errorMessages.add(errorMessage));
                 } catch (CommandException ex) {
                     logger.log(Level.SEVERE, "Error during ingest of file {0}", new Object[]{fileName});
+
+                    // Direct upload has already stored the file in S3.
+                    // Remove it if Dataverse rejects the upload.
+                    try {
+                        sio.delete();
+                    } catch (IOException deleteEx) {
+                        logger.log(
+                            Level.WARNING,
+                            "Failed to delete rejected direct upload {0}: {1}",
+                            new Object[]{fileName, deleteEx.getMessage()}
+                        );
+                    }
+
+                    // Show the actual command error to the user.
+                    errorMessages.add(ex.getMessage());
+                    return;
                 }
 
                 if (datafiles == null) {
diff --git a/src/main/webapp/editFilesFragment.xhtml b/src/main/webapp/editFilesFragment.xhtml
index 8cc47f05f1c..84d96d0c300 100644
--- a/src/main/webapp/editFilesFragment.xhtml
+++ b/src/main/webapp/editFilesFragment.xhtml
@@ -138,6 +138,31 @@
                                 $(fileUpload).prepend('<div id="dragdropMsg">#{bundle['file.selectToAdd.dragdropMsg']}</div>');
                             }
                         }
+                        function checkUploadLimits(files, maxFileSize, remainingQuota) {
+                            var fileUploadWidget = PF('fileUploadWidget');
+                            var totalSize = 0;
+                            for (var i = 0; i < files.length; i++) {
+                                if (maxFileSize !== null && files[i].size > maxFileSize) {
+                                    fileUploadWidget.clear();
+                                    fileUploadWidget.showMessage({summary: '#{bundle["file.edit.error.file_exceeds_limit"]}'});
+                                    fileUploadWidget.jq.find('.ui-messages-error-icon').remove();
+                                    return false;
+                                }
+                                totalSize += files[i].size;
+                            }
+
+                            if (remainingQuota !== null && totalSize > remainingQuota) {
+                                var message = '#{bundle["file.addreplace.error.quota_exceeded"]}'
+                                        .replace('{0}', fileUploadWidget.formatSize(totalSize))
+                                        .replace('{1}', fileUploadWidget.formatSize(remainingQuota));
+                                fileUploadWidget.clear();
+                                fileUploadWidget.showMessage({summary: message});
+                                fileUploadWidget.jq.find('.ui-messages-error-icon').remove();
+                                return false;
+                            }
+
+                            return true;
+                        }
                         function dropBoxUploadFinished(fileupload) {
                             $('button[id$="dropBoxUploadFinished"]').trigger('click');
                         }
@@ -147,7 +172,7 @@
                         
                         $(document).ready(function () {
                             uploadWidgetDropMsg();
-                             #{useDirectUpload ? 'setupDirectUpload(true);':''}
+                            setupDirectUpload(#{useDirectUpload}, #{empty EditDatafilesPage.maxFileUploadSizeInBytes ? 'null' : EditDatafilesPage.maxFileUploadSizeInBytes}, #{empty EditDatafilesPage.maxTotalUploadSizeInBytes ? 'null' : EditDatafilesPage.maxTotalUploadSizeInBytes});
                         });
                         //]]>
                     </script>
@@ -348,9 +373,9 @@
                     
                     <p:commandButton id="updateEditDataFilesButtonsForUpload" action="#{EditDatafilesPage.uploadFinished()}" update="datasetForm:editDataFilesButtons" rendered="#{showFileButtonUpdate}" style="display:none"/>
                     <p:commandButton id="updateEditDataFilesButtonsForDelete" action="#{EditDatafilesPage.deleteFilesCompleted()}" update="datasetForm:editDataFilesButtons" rendered="#{showFileButtonUpdate}" style="display:none"/>
-                    <p:commandButton id="AllUploadsFinished" action="#{EditDatafilesPage.uploadFinished()}" update="@([id$=filesButtons]),datasetForm:contentOfHttpPanel,datasetForm:fileUpload,datasetForm:dropBoxUserButton,datasetForm:uploadMessage,datasetForm:rsyncPanel,datasetForm:filesCounts,datasetForm:filesTable" oncomplete="javascript:uploadWidgetDropMsg();" style="display:none"/> 
-                    <p:commandButton id="dropBoxUploadFinished" action="#{EditDatafilesPage.uploadFinished()}" update="@([id$=filesButtons]),datasetForm:fileUpload,datasetForm:dropBoxUserButton,datasetForm:dropBoxUploadMessage,datasetForm:rsyncPanel,datasetForm:filesCounts,datasetForm:filesTable" style="display:none"/>
-                    <p:commandButton id="allDeletesFinished" action="#{EditDatafilesPage.deleteFilesCompleted()}" update="@([id$=filesButtons]),datasetForm:fileUpload,datasetForm:dropBoxUserButton,datasetForm:uploadMessage,datasetForm:rsyncPanel,datasetForm:filesCounts,datasetForm:filesTable" oncomplete="javascript:uploadWidgetDropMsg();" style="display:none"/> 
+                    <p:commandButton id="AllUploadsFinished" action="#{EditDatafilesPage.uploadFinished()}" update="@([id$=filesButtons]),datasetForm:contentOfHttpPanel,datasetForm:fileUpload,datasetForm:dropBoxUserButton,datasetForm:uploadMessage,datasetForm:rsyncPanel,datasetForm:filesCounts,datasetForm:filesTable" oncomplete="uploadWidgetDropMsg(); setupDirectUpload(#{useDirectUpload}, #{empty EditDatafilesPage.maxFileUploadSizeInBytes ? 'null' : EditDatafilesPage.maxFileUploadSizeInBytes}, #{empty EditDatafilesPage.maxTotalUploadSizeInBytes ? 'null' : EditDatafilesPage.maxTotalUploadSizeInBytes});" style="display:none"/>
+                    <p:commandButton id="dropBoxUploadFinished" action="#{EditDatafilesPage.uploadFinished()}" update="@([id$=filesButtons]),datasetForm:fileUpload,datasetForm:dropBoxUserButton,datasetForm:dropBoxUploadMessage,datasetForm:rsyncPanel,datasetForm:filesCounts,datasetForm:filesTable" oncomplete="setupDirectUpload(#{useDirectUpload}, #{empty EditDatafilesPage.maxFileUploadSizeInBytes ? 'null' : EditDatafilesPage.maxFileUploadSizeInBytes}, #{empty EditDatafilesPage.maxTotalUploadSizeInBytes ? 'null' : EditDatafilesPage.maxTotalUploadSizeInBytes});" style="display:none"/>
+                    <p:commandButton id="allDeletesFinished" action="#{EditDatafilesPage.deleteFilesCompleted()}" update="@([id$=filesButtons]),datasetForm:contentOfHttpPanel,datasetForm:fileUpload,datasetForm:dropBoxUserButton,datasetForm:uploadMessage,datasetForm:rsyncPanel,datasetForm:filesCounts,datasetForm:filesTable" oncomplete="uploadWidgetDropMsg(); setupDirectUpload(#{useDirectUpload}, #{empty EditDatafilesPage.maxFileUploadSizeInBytes ? 'null' : EditDatafilesPage.maxFileUploadSizeInBytes}, #{empty EditDatafilesPage.maxTotalUploadSizeInBytes ? 'null' : EditDatafilesPage.maxTotalUploadSizeInBytes});" style="display:none"/>
                     <!-- ????? TODO: How scalable are all these hidden update buttons ????? -->
                     <!-- ????? 
                     datasetForm:fileUpload,
@@ -625,7 +650,7 @@
         <p class="text-warning"><span class="glyphicon glyphicon-warning-sign"/> #{EditDatafilesPage.warningMessageForFileTypeDifferentPopUp}</p>
         <div class="button-block">
             <p:commandButton styleClass="btn btn-default" value="#{bundle['file.delete']}" onclick="PF('fileTypeDifferentPopup').hide()" oncomplete="uploadWidgetDropMsg();
-                                   #{useDirectUpload ? 'setupDirectUpload(true);': ''}"
+                                   setupDirectUpload(#{useDirectUpload}, #{empty EditDatafilesPage.maxFileUploadSizeInBytes ? 'null' : EditDatafilesPage.maxFileUploadSizeInBytes}, #{empty EditDatafilesPage.maxTotalUploadSizeInBytes ? 'null' : EditDatafilesPage.maxTotalUploadSizeInBytes});"
                              action="#{EditDatafilesPage.deleteFiles()}"
                              update=":#{p:resolveClientId('datasetForm:filesTable', view)},:messagePanel,:#{p:resolveClientId('datasetForm:fileUpload', view)},uploadMessage"/>
             <button class="btn btn-default" onclick="PF('fileTypeDifferentPopup').hide();" type="button">
@@ -643,7 +668,7 @@
                 </h:outputFormat>
             </p>
         <div class="button-block">
-            <p:commandButton  styleClass="btn btn-default" value="#{EditDatafilesPage.labelForDeleteFilesPopup}" onclick="PF('fileAlreadyExistsPopup').hide()" oncomplete="uploadWidgetDropMsg();"
+            <p:commandButton  styleClass="btn btn-default" value="#{EditDatafilesPage.labelForDeleteFilesPopup}" onclick="PF('fileAlreadyExistsPopup').hide()" oncomplete="uploadWidgetDropMsg(); setupDirectUpload(#{useDirectUpload}, #{empty EditDatafilesPage.maxFileUploadSizeInBytes ? 'null' : EditDatafilesPage.maxFileUploadSizeInBytes}, #{empty EditDatafilesPage.maxTotalUploadSizeInBytes ? 'null' : EditDatafilesPage.maxTotalUploadSizeInBytes});"
                               action="#{EditDatafilesPage.deleteDuplicateFiles()}"
                              update=":#{p:resolveClientId('datasetForm:filesTable', view)},:messagePanel,:#{p:resolveClientId('datasetForm:fileUpload', view)},uploadMessage,@([id$=filesButtons])"/>
             <button class="btn btn-default" onclick="PF('fileAlreadyExistsPopup').hide();" type="button">
diff --git a/src/main/webapp/editdatafiles.xhtml b/src/main/webapp/editdatafiles.xhtml
index dcd495d88a2..b548b9bdaba 100644
--- a/src/main/webapp/editdatafiles.xhtml
+++ b/src/main/webapp/editdatafiles.xhtml
@@ -77,6 +77,7 @@
                         <ui:param name="bean" value="#{EditDatafilesPage}"/>
                         <ui:param name="restrictFileAction" value="restrictFiles"/>
                         <ui:param name="deleteFileAction" value="deleteFiles"/>
+                        <ui:param name="deleteFileOncomplete" value="deleteFinished();"/>
                         <ui:param name="saveEmbargoAction" value="saveEmbargo"/>
                         <ui:param name="saveRetentionAction" value="saveRetention"/>
                         <ui:param name="updateElements" value=":datasetForm:embargoInputs"/>
diff --git a/src/main/webapp/file-edit-popup-fragment.xhtml b/src/main/webapp/file-edit-popup-fragment.xhtml
index 313d1f6bef8..f24cb8a4be1 100644
--- a/src/main/webapp/file-edit-popup-fragment.xhtml
+++ b/src/main/webapp/file-edit-popup-fragment.xhtml
@@ -264,7 +264,7 @@
         </ui:fragment>
         <div class="button-block">
             <p:commandButton styleClass="btn btn-default" value="#{bundle['file.delete']}" onclick="PF('deleteFileConfirmation').hide()" 
-                             action="#{bean[deleteFileAction]}"/>
+                             action="#{bean[deleteFileAction]}" oncomplete="#{deleteFileOncomplete}"/>
             <button class="btn btn-link" onclick="PF('deleteFileConfirmation').hide()" type="button">
                 #{bundle.cancel}
             </button>
diff --git a/src/main/webapp/resources/js/fileupload.js b/src/main/webapp/resources/js/fileupload.js
index 03ec82f214b..ae3e7ab285a 100644
--- a/src/main/webapp/resources/js/fileupload.js
+++ b/src/main/webapp/resources/js/fileupload.js
@@ -40,7 +40,7 @@ var finishFile = (function() {
 })();
 
 
-function setupDirectUpload(enabled) {
+function setupDirectUpload(enabled, maxFileSize, remainingQuota) {
     if (enabled) {
         directUploadEnabled = true;
         //An indicator as to which version is being used - should keep updated.
@@ -75,6 +75,16 @@ function setupDirectUpload(enabled) {
                 }
                 //Add support for drag and drop. Since the fileUploadForm is not replaced by PF, catching changes with a mutationobserver isn't needed
                 var fileDropWidget = document.getElementById('datasetForm:fileUpload');
+                fileDropWidget.addEventListener('change', function(event) {
+                    if (!checkUploadLimits(event.target.files, maxFileSize, remainingQuota)) {
+                        event.stopImmediatePropagation();
+                    }
+                }, true);
+                fileDropWidget.addEventListener('drop', function(event) {
+                    if (!checkUploadLimits(event.dataTransfer.files, maxFileSize, remainingQuota)) {
+                        event.stopImmediatePropagation();
+                    }
+                }, true);
                 fileDropWidget.addEventListener('drop', function(event) {
                     fileList = [];
                     for (var i = 0; i < event.dataTransfer.files.length; i++) {
@@ -87,11 +97,12 @@ function setupDirectUpload(enabled) {
                     mutations.forEach(function(mutation) {
                         for (i = 0; i < mutation.addedNodes.length; i++) {
                             //Add a listener on any replacement file 'select' widget
-                    if (mutation.addedNodes[i].id === 'datasetForm:fileUpload_input') {
+                            if (mutation.addedNodes[i].id === 'datasetForm:fileUpload_input') {
                                 fileInput = mutation.addedNodes[i];
                                 mutation.addedNodes[i].addEventListener('change', function(event) {
-                                    for (var j = 0; j < mutation.addedNodes[i].files.length; j++) {
-                                        queueFileForDirectUpload(mutation.addedNodes[i].files[j]);
+                                    var files = event.target.files;
+                                    for (var j = 0; j < files.length; j++) {
+                                        queueFileForDirectUpload(files[j]);
                                     }
                                 }, { once: false });
                             }
@@ -690,4 +701,4 @@ function getChecksum(blob, cbProgress) {
                         }
                 });
         });
-}
\ No newline at end of file
+}
diff --git a/src/test/java/edu/harvard/iq/dataverse/EditDatafilesPageTest.java b/src/test/java/edu/harvard/iq/dataverse/EditDatafilesPageTest.java
index 11578b71f0e..116ab055ed2 100644
--- a/src/test/java/edu/harvard/iq/dataverse/EditDatafilesPageTest.java
+++ b/src/test/java/edu/harvard/iq/dataverse/EditDatafilesPageTest.java
@@ -1,17 +1,26 @@
 package edu.harvard.iq.dataverse;
 
+import edu.harvard.iq.dataverse.storageuse.UploadSessionQuotaLimit;
+import edu.harvard.iq.dataverse.util.FileUtil;
+import edu.harvard.iq.dataverse.util.JsfHelper;
 import edu.harvard.iq.dataverse.util.SystemConfig;
 import org.junit.jupiter.api.Test;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
+import org.mockito.MockedStatic;
 import org.mockito.MockitoAnnotations;
 
+import java.lang.reflect.Field;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.when;
 
 class EditDatafilesPageTest {
@@ -61,4 +70,73 @@ void testPopulateHumanPerFormatTabularLimits_WithDefaultKey() {
         assertTrue(result.contains("csv: 10.0 MB"), "Expected CSV limit in human-readable format, but got: " + result);
         assertFalse(result.contains("default"), "Default key should be excluded from the output");
     }
-}
\ No newline at end of file
+
+    @Test
+    void testMaxTotalUploadSizeTracksCurrentUploadSessionQuota() throws Exception {
+        UploadSessionQuotaLimit quota = new UploadSessionQuotaLimit(100L, 80L);
+        Field quotaField = EditDatafilesPage.class.getDeclaredField("uploadSessionQuota");
+        quotaField.setAccessible(true);
+        quotaField.set(editDatafilesPage, quota);
+
+        assertEquals(20L, editDatafilesPage.getMaxTotalUploadSizeInBytes());
+        assertEquals("20 B", editDatafilesPage.getHumanMaxTotalUploadSizeInBytes());
+
+        quota.setTotalUsageInBytes(90L);
+
+        assertEquals(10L, editDatafilesPage.getMaxTotalUploadSizeInBytes());
+        assertEquals("10 B", editDatafilesPage.getHumanMaxTotalUploadSizeInBytes());
+    }
+
+    @Test
+    void testMaxTotalUploadSizeFallsBackToConfiguredLimitWithoutQuota() throws Exception {
+        Field limitField = EditDatafilesPage.class.getDeclaredField("maxTotalUploadSizeInBytes");
+        limitField.setAccessible(true);
+        limitField.set(editDatafilesPage, 25L);
+
+        assertEquals(25L, editDatafilesPage.getMaxTotalUploadSizeInBytes());
+        assertEquals("25 B", editDatafilesPage.getHumanMaxTotalUploadSizeInBytes());
+    }
+
+    @Test
+    void testDeletingUnsavedFileReleasesUploadQuota() throws Exception {
+        UploadSessionQuotaLimit quota = new UploadSessionQuotaLimit(100L, 90L);
+        Field quotaField = EditDatafilesPage.class.getDeclaredField("uploadSessionQuota");
+        quotaField.setAccessible(true);
+        quotaField.set(editDatafilesPage, quota);
+        DataFile dataFile = new DataFile();
+        dataFile.setFilesize(10L);
+        dataFile.setStorageIdentifier("test-storage-id");
+        FileMetadata fileMetadata = new FileMetadata();
+        fileMetadata.setDataFile(dataFile);
+        fileMetadata.setLabel("test.txt");
+        Dataset dataset = mock(Dataset.class);
+        DatasetVersion version = mock(DatasetVersion.class);
+        List<FileMetadata> displayedFiles = new ArrayList<>(List.of(fileMetadata));
+        List<FileMetadata> versionFiles = new ArrayList<>(List.of(fileMetadata));
+        List<DataFile> datasetFiles = new ArrayList<>(List.of(dataFile));
+        List<DataFile> newFiles = new ArrayList<>(List.of(dataFile));
+        when(dataset.getOrCreateEditVersion()).thenReturn(version);
+        when(version.getFileMetadatas()).thenReturn(versionFiles);
+        when(dataset.getFiles()).thenReturn(datasetFiles);
+        editDatafilesPage.setDataset(dataset);
+        editDatafilesPage.setMode(EditDatafilesPage.FileEditMode.UPLOAD);
+        editDatafilesPage.setFileMetadatas(displayedFiles);
+        editDatafilesPage.setSelectedFiles(List.of(fileMetadata));
+        Field newFilesField = EditDatafilesPage.class.getDeclaredField("newFiles");
+        newFilesField.setAccessible(true);
+        newFilesField.set(editDatafilesPage, newFiles);
+
+        try (MockedStatic<FileUtil> fileUtil = mockStatic(FileUtil.class);
+                MockedStatic<JsfHelper> jsfHelper = mockStatic(JsfHelper.class)) {
+            editDatafilesPage.deleteFiles();
+            fileUtil.verify(() -> FileUtil.deleteTempFile(dataFile, dataset, null));
+        }
+
+        assertEquals(20L, editDatafilesPage.getMaxTotalUploadSizeInBytes());
+        assertTrue(displayedFiles.isEmpty());
+        assertTrue(versionFiles.isEmpty());
+        assertTrue(datasetFiles.isEmpty());
+        assertTrue(newFiles.isEmpty());
+    }
+
+}