diff --git a/src/popup/popup.css b/src/popup/popup.css
index 438d4d2..0307f68 100644
--- a/src/popup/popup.css
+++ b/src/popup/popup.css
@@ -459,6 +459,21 @@ body {
   color: var(--text-light);
 }
 
+.pdf-item-status.failed {
+  color: var(--red);
+}
+
+/* Error details for erroneous documents */
+.pdf-item-error {
+  font-size: 10px;
+  color: var(--red);
+  margin-top: 4px;
+  padding: 4px 6px;
+  background: rgba(229, 57, 53, 0.08);
+  border-radius: 3px;
+  line-height: 1.3;
+}
+
 /* Price display */
 .pdf-price {
   font-weight: 600;
diff --git a/src/popup/popup.ts b/src/popup/popup.ts
index 9e483cc..02cc4f4 100644
--- a/src/popup/popup.ts
+++ b/src/popup/popup.ts
@@ -464,6 +464,9 @@ function renderPDFItem(pdf: DocumentProxy, section: 'pending' | 'basket' | 'prod
       break;
   }
 
+  // Show detailed error info for erroneous documents
+  const hasErrorDetails = pdf.binectStatus === 'failed' && pdf.errorMessage && pdf.binectStatusCode === 7;
+
   return `
     <div class="pdf-list-item ${statusClass}" data-id="${escapeHtml(pdf.id)}">
       <div class="pdf-item-icon">${getStatusIcon(pdf.binectStatus)}</div>
@@ -478,6 +481,7 @@ function renderPDFItem(pdf: DocumentProxy, section: 'pending' | 'basket' | 'prod
         </div>
         ${pdf.recipientAddress ? `<div class="pdf-item-recipient">${escapeHtml(pdf.recipientAddress.split('\n')[0])}</div>` : ''}
         <div class="pdf-item-status ${statusClass}">${statusText}</div>
+        ${hasErrorDetails ? `<div class="pdf-item-error">${escapeHtml(pdf.errorMessage!)}</div>` : ''}
       </div>
       <div class="pdf-item-actions">
         ${actionsHtml}
@@ -896,6 +900,8 @@ async function handleRefreshStatus(id: string) {
       newStatus = 'sent';
     } else if (result.status === 6) {
       newStatus = 'canceled';
+    } else if (result.status === 7) {
+      newStatus = 'failed';  // Erroneous
     } else if (result.status === 3 || result.status === 4) {
       newStatus = 'in_production';
     } else if (result.status === 2) {
@@ -906,7 +912,8 @@ async function handleRefreshStatus(id: string) {
       binectStatus: result.status,
       binectStatusText: result.statusText,
       price: result.price,
-      recipientAddress: result.recipientAddress
+      recipientAddress: result.recipientAddress,
+      errorMessage: result.errorDetails
     };
 
     // Update in background
@@ -923,6 +930,7 @@ async function handleRefreshStatus(id: string) {
     pdf.binectStatusText = result.statusText;
     if (result.price) pdf.price = result.price;
     if (result.recipientAddress) pdf.recipientAddress = result.recipientAddress;
+    if (result.errorDetails) pdf.errorMessage = result.errorDetails;
     renderPDFList();
 
   } catch (error) {
diff --git a/src/utils/binect-api.ts b/src/utils/binect-api.ts
index 060c248..053010f 100644
--- a/src/utils/binect-api.ts
+++ b/src/utils/binect-api.ts
@@ -334,6 +334,7 @@ export interface DocumentStatusInfo {
   statusText: string;
   price?: number;
   recipientAddress?: string;
+  errorDetails?: string;  // Error details for erroneous documents
 }
 
 /**
@@ -425,17 +426,25 @@ export async function getDocumentStatus(
     // Extract price and recipient if available
     let price: number | undefined;
     let recipientAddress: string | undefined;
+    let errorDetails: string | undefined;
 
     if (doc.letter?.letterData) {
       price = doc.letter.letterData.price?.priceAfterTax;
       recipientAddress = doc.letter.letterData.recipientAddress;
     }
 
+    // Extract error details for erroneous documents (status 7)
+    if (doc.status.code === 7 && doc.letter?.errors && doc.letter.errors.length > 0) {
+      errorDetails = doc.letter.errors.map(e => e.message).join('; ');
+      console.log('[Binect API] Document errors:', errorDetails);
+    }
+
     return {
       status: doc.status.code,
       statusText: doc.status.text || getStatusText(doc.status.code),
       price,
       recipientAddress,
+      errorDetails,
     };
   } catch (error) {
     console.error('[Binect API] Get status error:', error);