diff --git a/go/cmd/server/main.go b/go/cmd/server/main.go
index 284e75e5..1f126da3 100644
--- a/go/cmd/server/main.go
+++ b/go/cmd/server/main.go
@@ -82,7 +82,7 @@ func main() {
 	goRouter.HandleFunc("/attachments/{id}", attachmentHandler.Get).Methods("GET")
 	goRouter.HandleFunc("/attachments/{id}", attachmentHandler.Delete).Methods("DELETE")
 
-	// PDF generation routes
+	// PDF generation routes (must come BEFORE the file server PathPrefix handler)
 	goRouter.HandleFunc("/pdf/generate-invoice", handlers.GenerateInvoicePDF).Methods("POST")
 	goRouter.HandleFunc("/pdf/generate-quote", handlers.GenerateQuotePDF).Methods("POST")
 	goRouter.HandleFunc("/pdf/generate-po", handlers.GeneratePurchaseOrderPDF).Methods("POST")
@@ -90,10 +90,9 @@ func main() {
 	goRouter.HandleFunc("/pdf/generate-orderack", handlers.GenerateOrderAckPDF).Methods("POST")
 	goRouter.HandleFunc("/pdf/count-pages", handlers.CountPages).Methods("POST")
 
-	// Serve generated PDFs
+	// Serve generated PDFs (must come AFTER specific routes)
 	pdfDir := os.Getenv("PDF_OUTPUT_DIR")
 	if pdfDir == "" {
-		g
 		pdfDir = "webroot/pdf"
 	}
 	goRouter.PathPrefix("/pdf/").Handler(http.StripPrefix("/go/pdf/", http.FileServer(http.Dir(pdfDir))))
diff --git a/php/app/controllers/documents_controller.php b/php/app/controllers/documents_controller.php
index e8e67c4f..9ca90aa8 100755
--- a/php/app/controllers/documents_controller.php
+++ b/php/app/controllers/documents_controller.php
@@ -1554,4 +1554,22 @@ ENDINSTRUCTIONS;
 		}
 		return $newDoc[$model];
 	}
+
+	/**
+	 * Calculate invoice totals (subtotal, GST, total)
+	 * Used by the Go PDF endpoint
+	 */
+	function calculateInvoiceTotals($documentId) {
+		$document = $this->Document->find('first', array(
+			'conditions' => array('Document.id' => $documentId),
+			'recursive' => 1
+		));
+
+		if (empty($document)) {
+			return array('subtotal' => 0, 'gst' => 0, 'total' => 0);
+		}
+
+		$totals = $this->calculateTotals($document, $document['Invoice']['gst']);
+		return $totals;
+	}
 }
diff --git a/php/app/views/documents/pdf_invoice.ctp b/php/app/views/documents/pdf_invoice.ctp
index e5da9f87..df57026c 100755
--- a/php/app/views/documents/pdf_invoice.ctp
+++ b/php/app/views/documents/pdf_invoice.ctp
@@ -1,38 +1,99 @@
 <?php
-App::import('Vendor','pdfdoc');
+// Call the Go PDF generation endpoint instead of using TCPDF
+// Use environment variable for Go service URL, default to Docker DNS name and port
+$goHost = getenv('GO_APP_HOST') ?: 'cmc-go:8080';
+$goApiUrl = 'http://' . $goHost . '/go/pdf/generate-invoice';
 
-$pdfdoc = new PDFDOC();
+// Prepare invoice data for Go API
+$billTo = isset($document['Document']['bill_to']) ? $document['Document']['bill_to'] : '';
+$shipTo = isset($document['Document']['ship_to']) ? $document['Document']['ship_to'] : '';
+$shippingDetails = isset($document['Document']['shipping_details']) ? $document['Document']['shipping_details'] : 'TBA';
+$customerOrderNumber = isset($document['Document']['customer_order_number']) ? $document['Document']['customer_order_number'] : '';
+$paymentTerms = isset($document['Document']['payment_terms']) ? $document['Document']['payment_terms'] : '';
+$customerABN = isset($document['Document']['customer_abn']) ? $document['Document']['customer_abn'] : '';
 
-$pdfdoc->SetPrintHeader(false);
-$pdfdoc->SetPrintFooter(false);
+// Calculate totals
+$totals = $this->requestAction('/documents/calculateInvoiceTotals/'.$document['Document']['id']);
+$subtotal = isset($totals['subtotal']) ? $totals['subtotal'] : 0;
+$gstAmount = isset($totals['gst']) ? $totals['gst'] : 0;
+$total = isset($totals['total']) ? $totals['total'] : 0;
 
+// Prepare line items
+$lineItems = array();
+foreach ($document['LineItem'] as $item) {
+    $lineItems[] = array(
+        'item_number' => $item['item_number'],
+        'quantity' => $item['quantity'],
+        'title' => $item['title'],
+        'description' => isset($item['description']) ? $item['description'] : '',
+        'unit_price' => isset($item['unit_price_string']) ? floatval($item['unit_price_string']) : 0,
+        'total_price' => isset($item['gross_price_string']) ? floatval($item['gross_price_string']) : 0
+    );
+}
 
-$pdfdoc->AddPage();
-$pdfdoc->Page1Header();
+$invoicePayload = array(
+    'document_id' => $document['Document']['id'],
+    'invoice_title' => $document['Invoice']['title'],
+    'customer_name' => $document['Customer']['name'],
+    'contact_email' => isset($document['Contact']['email']) ? $document['Contact']['email'] : '',
+    'contact_name' => isset($document['Contact']['first_name']) ? $document['Contact']['first_name'] . ' ' . $document['Contact']['last_name'] : '',
+    'user_first_name' => isset($user['User']['first_name']) ? $user['User']['first_name'] : '',
+    'user_last_name' => isset($user['User']['last_name']) ? $user['User']['last_name'] : '',
+    'user_email' => isset($user['User']['email']) ? $user['User']['email'] : '',
+    'your_reference' => isset($document['Document']['your_reference']) ? $document['Document']['your_reference'] : '',
+    'ship_via' => isset($ship_via) ? $ship_via : '',
+    'fob' => isset($fob) ? $fob : '',
+    'issue_date' => $document['Invoice']['issue_date'],
+    'issue_date_string' => isset($issue_date_string) ? $issue_date_string : date('d F Y', strtotime($document['Invoice']['issue_date'])),
+    'currency_symbol' => isset($document['Currency']['symbol']) ? $document['Currency']['symbol'] : '$',
+    'currency_code' => isset($document['Currency']['code']) ? $document['Currency']['code'] : 'AUD',
+    'show_gst' => $document['Invoice']['gst'],
+    'bill_to' => $billTo,
+    'ship_to' => $shipTo,
+    'shipping_details' => $shippingDetails,
+    'customer_order_number' => $customerOrderNumber,
+    'job_title' => isset($job['Job']['title']) ? $job['Job']['title'] : '',
+    'payment_terms' => $paymentTerms,
+    'customer_abn' => $customerABN,
+    'subtotal' => $subtotal,
+    'gst_amount' => $gstAmount,
+    'total' => $total,
+    'line_items' => $lineItems,
+    'output_dir' => '../php/app/webroot/pdf'
+);
 
-$pageTitle = "<h1>TAX INVOICE</h1>";
-$pdfdoc->writeHTML($pageTitle, true, false, false, false, 'C');
+// Call Go API
+$ch = curl_init($goApiUrl);
+curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
+curl_setopt($ch, CURLOPT_POST, true);
+curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($invoicePayload));
+curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
+curl_setopt($ch, CURLOPT_TIMEOUT, 30);
 
-$pdfdoc->SetTextColor(0);
-
-$pageNo = $pdfdoc->PageNoFormatted();
-$totalCount = $pdfdoc->getAliasNbPages();
-
-
-$shippingBillingBox = $this->element('pdf_shipping_billing_box', array('pageNo'=>$pageNo, 'totalCount'=>$totalCount));
-
-$pdfdoc->writeHTML($shippingBillingBox, false);
-
-$LineItemTable = $this->element('line_items_table_with_shipping');
-$pdfdoc->SetPrintHeader(true);
-
-$pdfdoc->pageContent($LineItemTable);
-
-$this->element('pdf_output', array('pdfdoc'=>$pdfdoc));
+$response = curl_exec($ch);
+$curlError = curl_error($ch);
+$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+curl_close($ch);
 
+if ($httpCode === 200) {
+    $result = json_decode($response, true);
+    if (isset($result['filename'])) {
+        echo "<script type=\"text/javascript\">
+            window.location.replace(\"/documents/view/{$document['Document']['id']}\");
+        </script>";
+    } else {
+        echo "Error: Invalid response from PDF generator";
+    }
+} else {
+    echo "Error: PDF generation failed (HTTP {$httpCode})<br>";
+    echo "API URL: " . htmlspecialchars($goApiUrl) . "<br>";
+    if (!empty($curlError)) {
+        echo "Curl Error: " . htmlspecialchars($curlError) . "<br>";
+    }
+    if (!empty($response)) {
+        echo "<pre>" . htmlspecialchars($response) . "</pre>";
+    }
+}
 ?>
 
-<script type="text/javascript">
-    window.location.replace("/documents/view/<?=$document['Document']['id']?>");
-</script>
-
diff --git a/php/app/webroot/pdf/.pdf b/php/app/webroot/pdf/.pdf
new file mode 100644
index 00000000..7acc2ce5
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diff --git a/php/app/webroot/pdf/CMCPL10361.pdf b/php/app/webroot/pdf/CMCPL10361.pdf
new file mode 100644
index 00000000..1536d621
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diff --git a/php/app/webroot/pdf/CMCPO5421-Rev1_1.pdf b/php/app/webroot/pdf/CMCPO5421-Rev1_1.pdf
new file mode 100644
index 00000000..2e1c9c5b
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diff --git a/php/app/webroot/pdf/_3.pdf b/php/app/webroot/pdf/_3.pdf
new file mode 100644
index 00000000..cb7faccb
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