diff --git a/lib/upload-manager.js b/lib/upload-manager.js
index 8cfeaf4..0068dc7 100644
--- a/lib/upload-manager.js
+++ b/lib/upload-manager.js
@@ -698,21 +698,23 @@ class UploadManager extends EventEmitter {
   }
 
   addJobs(tasks) {
-    if (!this.running || !tasks || tasks.length === 0) return;
+    if (!this.running || !tasks || tasks.length === 0) return 0;
     const { signal } = this.abortController;
     const results = this._batchResults || new Map();
+    let added = 0;
     for (const task of tasks) {
+      // Skip if this job is already being processed (prevent duplicates)
+      if (task.jobId && this.jobAbortControllers.has(task.jobId)) continue;
       const fileName = path.basename(task.file);
       if (!results.has(task.file)) {
         let size = 0;
         try { size = fs.statSync(task.file).size; } catch {}
         results.set(task.file, { name: fileName, size, results: [] });
       }
-    }
-    // Start each new job and track promises so batch-done waits for them
-    for (const task of tasks) {
       this._additionalPromises.push(this._runJob(task, results, signal));
+      added++;
     }
+    return added;
   }
 
   cancelJobs(jobIds) {
diff --git a/main.js b/main.js
index 0f61f26..f758bc9 100644
--- a/main.js
+++ b/main.js
@@ -786,9 +786,9 @@ ipcMain.handle('add-jobs-to-batch', (_event, payload) => {
   const jobs = payload && Array.isArray(payload.jobs) ? payload.jobs : [];
   const tasks = buildUploadTasksFromJobs(config, jobs);
   if (tasks.length === 0) return { added: 0 };
-  uploadManager.addJobs(tasks);
-  debugLog(`add-jobs-to-batch: added ${tasks.length} tasks to running batch`);
-  return { added: tasks.length };
+  const added = uploadManager.addJobs(tasks);
+  debugLog(`add-jobs-to-batch: ${added} of ${tasks.length} tasks added (${tasks.length - added} already in batch)`);
+  return { added };
 });
 
 ipcMain.handle('finish-after-active', () => {
diff --git a/renderer/app.js b/renderer/app.js
index 108ab49..ca91688 100644
--- a/renderer/app.js
+++ b/renderer/app.js
@@ -1354,25 +1354,28 @@ function _markSkippedJobs(result) {
 
 async function startSelectedUpload() {
   if (uploading) {
-    // Batch already running — only add error/aborted/skipped jobs (not already-queued ones)
-    const retryable = queueJobs.filter(j => selectedJobIds.has(j.id) && ['error', 'aborted', 'skipped'].includes(j.status));
-    if (retryable.length > 0) {
-      retryable.forEach(j => {
+    // Batch already running — add selected jobs (queued/error/aborted/skipped) to running batch
+    // Upload-manager has duplicate protection (skips jobs already tracked)
+    const addable = queueJobs.filter(j => selectedJobIds.has(j.id) && ['queued', 'error', 'aborted', 'skipped'].includes(j.status));
+    if (addable.length > 0) {
+      addable.forEach(j => {
         j.status = 'queued'; j.error = null; j.result = null;
         j.bytesUploaded = 0; j.speedKbs = 0; j.progress = 0; j.uploadId = null;
       });
       renderQueueTable();
       const result = await window.api.addJobsToBatch({
-        jobs: retryable.map(j => ({ id: j.id, file: j.file, fileName: j.fileName, hoster: j.hoster }))
+        jobs: addable.map(j => ({ id: j.id, file: j.file, fileName: j.fileName, hoster: j.hoster }))
       });
       _markSkippedJobs(result);
       persistQueueStateSoon();
-      showCopyToast(`${retryable.length} Jobs zum laufenden Upload hinzugefügt`);
-    } else {
-      // All selected jobs are already queued/uploading — just inform user
-      const waiting = queueJobs.filter(j => selectedJobIds.has(j.id) && j.status === 'queued');
-      if (waiting.length > 0) {
-        showCopyToast(`${waiting.length} Jobs warten bereits auf ihren Upload-Slot`);
+      const added = result && result.added || 0;
+      const alreadyInBatch = addable.length - added;
+      if (added > 0 && alreadyInBatch > 0) {
+        showCopyToast(`${added} Jobs hinzugefügt, ${alreadyInBatch} waren schon im Batch`);
+      } else if (added > 0) {
+        showCopyToast(`${added} Jobs zum laufenden Upload hinzugefügt`);
+      } else {
+        showCopyToast(`${addable.length} Jobs sind bereits im laufenden Batch`);
       }
     }
     return;