update

ts/formats/ubl/generic/ubl.encoder.ts

@@ -82,11 +82,18 @@ export class UBLEncoder extends UBLBaseEncoder {
     const typeCode = documentType === UBLDocumentType.INVOICE ? '380' : '381';
     this.appendElement(doc, root, 'cbc:InvoiceTypeCode', typeCode);
     
-    // Notes
+    // Notes - include subject as first note if it exists
+    const allNotes: string[] = [];
+    if (invoice.subject && invoice.subject.trim()) {
+      allNotes.push(invoice.subject);
+    }
     if (invoice.notes && invoice.notes.length > 0) {
-      for (const note of invoice.notes) {
-        this.appendElement(doc, root, 'cbc:Note', note);
-      }
+      allNotes.push(...invoice.notes);
+    }
+    
+    // Write all notes
+    for (const note of allNotes) {
+      this.appendElement(doc, root, 'cbc:Note', note);
     }
     
     // Document Currency Code

ts/formats/ubl/xrechnung/xrechnung.decoder.ts

@@ -164,18 +164,31 @@ export class XRechnungDecoder extends UBLBaseDecoder {
       const periodEnd = this.getText('//cac:InvoicePeriod/cbc:EndDate', this.doc);
       const deliveryDate = this.getText('//cac:Delivery/cbc:ActualDeliveryDate', this.doc);
 
-      // Extract notes
-      const notes: string[] = [];
-      const noteNodes = this.select('//cbc:Note', this.doc);
+      // Extract notes (excluding PaymentTerms notes)
+      const allNotes: string[] = [];
+      const noteNodes = this.select('//cbc:Note[not(parent::cac:PaymentTerms)]', this.doc);
       if (noteNodes && Array.isArray(noteNodes)) {
         for (let i = 0; i < noteNodes.length; i++) {
           const noteText = noteNodes[i].textContent || '';
           if (noteText) {
-            notes.push(noteText);
+            allNotes.push(noteText);
           }
         }
       }
 
+      // Extract subject and notes separately
+      // If we have notes, the first one might be the subject
+      let subject = `Invoice ${invoiceId}`;
+      let notes = [...allNotes];
+      
+      // If the first note doesn't look like a payment term or other standard note,
+      // treat it as the subject
+      if (allNotes.length > 0 && !allNotes[0].toLowerCase().includes('due in') && 
+          !allNotes[0].toLowerCase().includes('payment')) {
+        subject = allNotes[0];
+        notes = allNotes.slice(1); // Remove subject from notes
+      }
+
       // Extract seller and buyer information
       const seller = this.extractParty('//cac:AccountingSupplierParty/cac:Party');
       const buyer = this.extractParty('//cac:AccountingCustomerParty/cac:Party');
@@ -196,7 +209,7 @@ export class XRechnungDecoder extends UBLBaseDecoder {
         incidenceId: invoiceId,
         from: seller,
         to: buyer,
-        subject: notes.length > 0 ? notes[0] : `Invoice ${invoiceId}`,
+        subject: subject,
         items: items,
         dueInDays: dueInDays,
         reverseCharge: false,