diff --git a/public/app.js b/public/app.js
index 15e0edc..4bac4e7 100644
--- a/public/app.js
+++ b/public/app.js
@@ -78,7 +78,7 @@ window.customerSearch = customerSearch;
 document.addEventListener('DOMContentLoaded', () => {
     loadCustomers();
     loadQuotes();
-    loadInvoices();
+    //loadInvoices();
     setDefaultDate();
     checkCurrentLogo();
     
@@ -755,33 +755,37 @@ async function fetchNextInvoiceNumber() {
 }
 
 async function loadInvoices() {
+    // Wird vom invoice-view.js Modul überschrieben (window.loadInvoices)
+    // Dieser Fallback lädt die Daten falls das Modul noch nicht geladen ist
     try {
         const response = await fetch('/api/invoices');
         invoices = await response.json();
-        renderInvoices();
+        // Falls das Modul geladen ist, nutze dessen Renderer
+        if (window.invoiceView) {
+            window.invoiceView.renderInvoiceView();
+        } else {
+            renderInvoices();
+        }
     } catch (error) {
         console.error('Error loading invoices:', error);
-        alert('Error loading invoices');
     }
 }
 
 function renderInvoices() {
+    if (window.invoiceView) {
+        window.invoiceView.renderInvoiceView();
+        return;
+    }
+    // Minimaler Fallback falls Modul nicht geladen
     const tbody = document.getElementById('invoices-list');
     tbody.innerHTML = invoices.map(invoice => `
         <tr>
-            <td class="px-6 py-4 whitespace-nowrap text-sm font-medium text-gray-900">${invoice.invoice_number}</td>
+            <td class="px-6 py-4 text-sm font-medium text-gray-900">${invoice.invoice_number}</td>
             <td class="px-6 py-4 text-sm text-gray-500">${invoice.customer_name || 'N/A'}</td>
-            <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500">${formatDate(invoice.invoice_date)}</td>
-            <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500">${invoice.terms}</td>
-            <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-900 font-semibold">$${parseFloat(invoice.total).toFixed(2)}</td>
-            <td class="px-6 py-4 whitespace-nowrap text-sm font-medium space-x-2">
-                <button onclick="viewInvoicePDF(${invoice.id})" class="text-green-600 hover:text-green-900">PDF</button>
-                <button onclick="exportToQBO(${invoice.id})" class="text-orange-600 hover:text-orange-900" title="Export to QuickBooks">
-                    QBO Export
-                </button>
-                <button onclick="editInvoice(${invoice.id})" class="text-blue-600 hover:text-blue-900">Edit</button>
-                <button onclick="deleteInvoice(${invoice.id})" class="text-red-600 hover:text-red-900">Delete</button>
-            </td>
+            <td class="px-6 py-4 text-sm text-gray-500">${formatDate(invoice.invoice_date)}</td>
+            <td class="px-6 py-4 text-sm text-gray-500">${invoice.terms}</td>
+            <td class="px-6 py-4 text-sm font-semibold">$${parseFloat(invoice.total).toFixed(2)}</td>
+            <td class="px-6 py-4 text-sm">Loading module...</td>
         </tr>
     `).join('');
 }
@@ -1125,38 +1129,13 @@ async function deleteInvoice(id) {
 }
 
 function viewInvoicePDF(id) {
-    window.open(`/api/invoices/${id}/pdf`, '_blank');
-}
-
-// *** FIX 2: Verbesserte Erfolgsmeldung mit QBO DocNumber ***
-async function exportToQBO(id) {
-    if (!confirm('Rechnung wirklich an QuickBooks Online senden?')) return;
-
-    // UI Feedback (einfach, aber wirksam)
-    const btn = event.target; // Der geklickte Button
-    const originalText = btn.textContent;
-    btn.textContent = "⏳...";
-    btn.disabled = true;
-
-    try {
-        const response = await fetch(`/api/invoices/${id}/export`, { method: 'POST' });
-        const result = await response.json();
-
-        if (response.ok) {
-            alert(`✅ Erfolg! QBO ID: ${result.qbo_id}, Rechnungsnr: ${result.qbo_doc_number}`);
-            // Liste neu laden um aktualisierte invoice_number anzuzeigen
-            loadInvoices(); 
-        } else {
-            alert(`❌ Fehler: ${result.error}`);
-        }
-    } catch (error) {
-        console.error(error);
-        alert('Netzwerkfehler beim Export.');
-    } finally {
-        btn.textContent = originalText;
-        btn.disabled = false;
+    if (window.invoiceView) {
+        window.invoiceView.viewPDF(id);
+    } else {
+        window.open(`/api/invoices/${id}/pdf`, '_blank');
     }
 }
+
 async function checkQboOverdue() {
     const btn = document.querySelector('button[onclick="checkQboOverdue()"]');
     const resultDiv = document.getElementById('qbo-result');
@@ -1263,3 +1242,4 @@ async function importFromQBO() {
         btn.disabled = false;
     }
 }
+window.openInvoiceModal = openInvoiceModal;
\ No newline at end of file
diff --git a/public/index.html b/public/index.html
index af86a9b..d13275b 100644
--- a/public/index.html
+++ b/public/index.html
@@ -67,13 +67,16 @@
 
             <!-- Invoices Tab -->
             <div id="invoices-tab" class="tab-content hidden">
-                <div class="flex justify-between items-center mb-6">
+                <div class="flex justify-between items-center mb-4">
                     <h2 class="text-3xl font-bold text-gray-800">Invoices</h2>
                     <button onclick="openInvoiceModal()" class="bg-blue-600 hover:bg-blue-700 text-white px-6 py-3 rounded-lg font-semibold shadow-md">
                         + New Invoice
                     </button>
                 </div>
 
+                <!-- Toolbar wird von invoice-view.js injiziert -->
+                <div id="invoice-toolbar"></div>
+
                 <div class="bg-white rounded-lg shadow-md overflow-hidden">
                     <table class="min-w-full divide-y divide-gray-200">
                         <thead class="bg-gray-50">
@@ -551,5 +554,6 @@
     </div>
 
     <script src="app.js"></script>
+    <script type="module" src="invoice-view-init.js"></script>
 </body>
 </html>
\ No newline at end of file
diff --git a/public/invoice-view-init.js b/public/invoice-view-init.js
new file mode 100644
index 0000000..44f85ea
--- /dev/null
+++ b/public/invoice-view-init.js
@@ -0,0 +1,25 @@
+// invoice-view-init.js — Bootstrap-Script (type="module")
+// Wird in index.html als <script type="module"> geladen.
+// Importiert das Invoice-View Modul und verbindet es mit der bestehenden App.
+
+import { loadInvoices, renderInvoiceView, injectToolbar } from './invoice-view.js';
+
+// Warte bis DOM fertig ist
+if (document.readyState === 'loading') {
+    document.addEventListener('DOMContentLoaded', init);
+} else {
+    init();
+}
+
+function init() {
+    // Toolbar injizieren
+    injectToolbar();
+    
+    // Globale Funktionen für app.js verfügbar machen
+    // (app.js ruft loadInvoices() auf wenn der Tab gewechselt wird)
+    window.loadInvoices = loadInvoices;
+    window.renderInvoices = renderInvoiceView;
+    
+    // Initiales Laden
+    loadInvoices();
+}
\ No newline at end of file
diff --git a/public/invoice-view.js b/public/invoice-view.js
new file mode 100644
index 0000000..612dadc
--- /dev/null
+++ b/public/invoice-view.js
@@ -0,0 +1,503 @@
+// invoice-view.js — ES Module für die Invoice View
+// Features: Status Filter (all/unpaid/paid/overdue), Customer Filter,
+// Group by (none/week/month), Sortierung neueste zuerst, Mark Paid/Unpaid
+
+// ============================================================
+// State
+// ============================================================
+let invoices = [];
+let filterCustomer = '';
+let filterStatus = 'unpaid';  // 'all' | 'unpaid' | 'paid' | 'overdue'
+let groupBy = 'none';         // 'none' | 'week' | 'month'
+
+const OVERDUE_DAYS = 30;
+
+// ============================================================
+// Helpers
+// ============================================================
+
+function formatDate(date) {
+    const d = new Date(date);
+    const month = String(d.getMonth() + 1).padStart(2, '0');
+    const day = String(d.getDate()).padStart(2, '0');
+    const year = d.getFullYear();
+    return `${month}/${day}/${year}`;
+}
+
+function daysSince(date) {
+    const d = new Date(date);
+    const now = new Date();
+    return Math.floor((now - d) / 86400000);
+}
+
+function getWeekNumber(date) {
+    const d = new Date(date);
+    d.setHours(0, 0, 0, 0);
+    d.setDate(d.getDate() + 3 - ((d.getDay() + 6) % 7));
+    const week1 = new Date(d.getFullYear(), 0, 4);
+    return {
+        year: d.getFullYear(),
+        week: 1 + Math.round(((d - week1) / 86400000 - 3 + ((week1.getDay() + 6) % 7)) / 7)
+    };
+}
+
+function getWeekRange(year, weekNum) {
+    const jan4 = new Date(year, 0, 4);
+    const dayOfWeek = jan4.getDay() || 7;
+    const monday = new Date(jan4);
+    monday.setDate(jan4.getDate() - dayOfWeek + 1 + (weekNum - 1) * 7);
+    const sunday = new Date(monday);
+    sunday.setDate(monday.getDate() + 6);
+    return { start: formatDate(monday), end: formatDate(sunday) };
+}
+
+function getMonthName(monthIndex) {
+    return ['January','February','March','April','May','June',
+            'July','August','September','October','November','December'][monthIndex];
+}
+
+function isPaid(inv) {
+    return !!inv.paid_date;
+}
+
+function isOverdue(inv) {
+    return !isPaid(inv) && daysSince(inv.invoice_date) > OVERDUE_DAYS;
+}
+
+// ============================================================
+// Data Loading
+// ============================================================
+
+export async function loadInvoices() {
+    try {
+        const response = await fetch('/api/invoices');
+        invoices = await response.json();
+        renderInvoiceView();
+    } catch (error) {
+        console.error('Error loading invoices:', error);
+    }
+}
+
+export function getInvoicesData() {
+    return invoices;
+}
+
+// ============================================================
+// Filtering & Sorting & Grouping
+// ============================================================
+
+function getFilteredInvoices() {
+    let filtered = [...invoices];
+
+    // Status Filter
+    if (filterStatus === 'unpaid') {
+        filtered = filtered.filter(inv => !isPaid(inv));
+    } else if (filterStatus === 'paid') {
+        filtered = filtered.filter(inv => isPaid(inv));
+    } else if (filterStatus === 'overdue') {
+        filtered = filtered.filter(inv => isOverdue(inv));
+    }
+    // 'all' → kein Filter
+
+    // Customer Filter
+    if (filterCustomer.trim()) {
+        const search = filterCustomer.toLowerCase();
+        filtered = filtered.filter(inv =>
+            (inv.customer_name || '').toLowerCase().includes(search)
+        );
+    }
+
+    // Sortierung: neueste zuerst
+    filtered.sort((a, b) => new Date(b.invoice_date) - new Date(a.invoice_date));
+
+    return filtered;
+}
+
+function groupInvoices(filtered) {
+    if (groupBy === 'none') return null;
+
+    const groups = new Map();
+
+    filtered.forEach(inv => {
+        const d = new Date(inv.invoice_date);
+        let key, label;
+
+        if (groupBy === 'week') {
+            const wk = getWeekNumber(inv.invoice_date);
+            key = `${wk.year}-W${String(wk.week).padStart(2, '0')}`;
+            const range = getWeekRange(wk.year, wk.week);
+            label = `Week ${wk.week}, ${wk.year} (${range.start} – ${range.end})`;
+        } else if (groupBy === 'month') {
+            const month = d.getMonth();
+            const year = d.getFullYear();
+            key = `${year}-${String(month).padStart(2, '0')}`;
+            label = `${getMonthName(month)} ${year}`;
+        }
+
+        if (!groups.has(key)) {
+            groups.set(key, { label, invoices: [], total: 0 });
+        }
+        const group = groups.get(key);
+        group.invoices.push(inv);
+        group.total += parseFloat(inv.total) || 0;
+    });
+
+    // Innerhalb jeder Gruppe nochmal nach Datum sortieren (neueste zuerst)
+    for (const group of groups.values()) {
+        group.invoices.sort((a, b) => new Date(b.invoice_date) - new Date(a.invoice_date));
+    }
+
+    // Gruppen nach Key sortieren (neueste zuerst)
+    return new Map([...groups.entries()].sort((a, b) => b[0].localeCompare(a[0])));
+}
+
+// ============================================================
+// Rendering
+// ============================================================
+
+function renderInvoiceRow(invoice) {
+    const hasQbo = !!invoice.qbo_id;
+    const paid = isPaid(invoice);
+    const overdue = isOverdue(invoice);
+
+    // QBO Button
+    const qboButton = hasQbo
+        ? `<span class="text-gray-400 text-xs" title="Already in QBO (ID: ${invoice.qbo_id})">✓ QBO</span>`
+        : `<button onclick="window.invoiceView.exportToQBO(${invoice.id})" class="text-orange-600 hover:text-orange-900" title="Export to QuickBooks">QBO Export</button>`;
+
+    // Paid/Unpaid Toggle Button
+    const paidButton = paid
+        ? `<button onclick="window.invoiceView.markUnpaid(${invoice.id})" class="text-yellow-600 hover:text-yellow-800" title="Mark as unpaid">↩ Unpaid</button>`
+        : `<button onclick="window.invoiceView.markPaid(${invoice.id})" class="text-emerald-600 hover:text-emerald-800" title="Mark as paid">💰 Paid</button>`;
+
+    // Status Badge
+    let statusBadge = '';
+    if (paid) {
+        statusBadge = `<span class="inline-block px-2 py-0.5 text-xs font-semibold rounded-full bg-green-100 text-green-800" title="Paid ${formatDate(invoice.paid_date)}">Paid</span>`;
+    } else if (overdue) {
+        statusBadge = `<span class="inline-block px-2 py-0.5 text-xs font-semibold rounded-full bg-red-100 text-red-800" title="${daysSince(invoice.invoice_date)} days old">Overdue</span>`;
+    }
+
+    // Row styling
+    const rowClass = paid ? 'bg-green-50/50' : overdue ? 'bg-red-50/50' : '';
+
+    return `
+        <tr class="${rowClass}">
+            <td class="px-6 py-4 whitespace-nowrap text-sm font-medium text-gray-900">
+                ${invoice.invoice_number} ${statusBadge}
+            </td>
+            <td class="px-6 py-4 text-sm text-gray-500">${invoice.customer_name || 'N/A'}</td>
+            <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500">${formatDate(invoice.invoice_date)}</td>
+            <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500">${invoice.terms}</td>
+            <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-900 font-semibold">$${parseFloat(invoice.total).toFixed(2)}</td>
+            <td class="px-6 py-4 whitespace-nowrap text-sm font-medium space-x-2">
+                <button onclick="window.invoiceView.viewPDF(${invoice.id})" class="text-green-600 hover:text-green-900">PDF</button>
+                <button onclick="window.invoiceView.viewHTML(${invoice.id})" class="text-teal-600 hover:text-teal-900">HTML</button>
+                ${qboButton}
+                ${paidButton}
+                <button onclick="window.invoiceView.edit(${invoice.id})" class="text-blue-600 hover:text-blue-900">Edit</button>
+                <button onclick="window.invoiceView.remove(${invoice.id})" class="text-red-600 hover:text-red-900">Delete</button>
+            </td>
+        </tr>
+    `;
+}
+
+function renderGroupHeader(label) {
+    return `
+        <tr class="bg-blue-50">
+            <td colspan="6" class="px-6 py-3 text-sm font-bold text-blue-800">
+                📅 ${label}
+            </td>
+        </tr>
+    `;
+}
+
+function renderGroupFooter(total, count) {
+    return `
+        <tr class="bg-gray-50 border-t-2 border-gray-300">
+            <td colspan="4" class="px-6 py-3 text-sm font-bold text-gray-700 text-right">Group Total (${count} invoices):</td>
+            <td class="px-6 py-3 text-sm font-bold text-gray-900">$${total.toFixed(2)}</td>
+            <td></td>
+        </tr>
+    `;
+}
+
+export function renderInvoiceView() {
+    const tbody = document.getElementById('invoices-list');
+    if (!tbody) return;
+
+    const filtered = getFilteredInvoices();
+    const groups = groupInvoices(filtered);
+
+    let html = '';
+    let grandTotal = 0;
+
+    if (groups) {
+        for (const [key, group] of groups) {
+            html += renderGroupHeader(group.label);
+            group.invoices.forEach(inv => {
+                html += renderInvoiceRow(inv);
+            });
+            html += renderGroupFooter(group.total, group.invoices.length);
+            grandTotal += group.total;
+        }
+
+        if (groups.size > 1) {
+            html += `
+                <tr class="bg-blue-100 border-t-4 border-blue-400">
+                    <td colspan="4" class="px-6 py-4 text-base font-bold text-blue-900 text-right">Grand Total (${filtered.length} invoices):</td>
+                    <td class="px-6 py-4 text-base font-bold text-blue-900">$${grandTotal.toFixed(2)}</td>
+                    <td></td>
+                </tr>
+            `;
+        }
+    } else {
+        filtered.forEach(inv => {
+            html += renderInvoiceRow(inv);
+            grandTotal += parseFloat(inv.total) || 0;
+        });
+
+        if (filtered.length > 0) {
+            html += `
+                <tr class="bg-gray-100 border-t-2 border-gray-300">
+                    <td colspan="4" class="px-6 py-3 text-sm font-bold text-gray-700 text-right">Total (${filtered.length} invoices):</td>
+                    <td class="px-6 py-3 text-sm font-bold text-gray-900">$${grandTotal.toFixed(2)}</td>
+                    <td></td>
+                </tr>
+            `;
+        }
+    }
+
+    if (filtered.length === 0) {
+        html = `<tr><td colspan="6" class="px-6 py-8 text-center text-gray-500">No invoices found.</td></tr>`;
+    }
+
+    tbody.innerHTML = html;
+
+    // Update count badge
+    const countEl = document.getElementById('invoice-count');
+    if (countEl) countEl.textContent = filtered.length;
+
+    // Update status button active states
+    updateStatusButtons();
+}
+
+function updateStatusButtons() {
+    document.querySelectorAll('[data-status-filter]').forEach(btn => {
+        const status = btn.getAttribute('data-status-filter');
+        if (status === filterStatus) {
+            btn.classList.remove('bg-white', 'text-gray-600');
+            btn.classList.add('bg-blue-600', 'text-white');
+        } else {
+            btn.classList.remove('bg-blue-600', 'text-white');
+            btn.classList.add('bg-white', 'text-gray-600');
+        }
+    });
+
+    // Update overdue count badge
+    const overdueCount = invoices.filter(inv => isOverdue(inv)).length;
+    const overdueBadge = document.getElementById('overdue-badge');
+    if (overdueBadge) {
+        if (overdueCount > 0) {
+            overdueBadge.textContent = overdueCount;
+            overdueBadge.classList.remove('hidden');
+        } else {
+            overdueBadge.classList.add('hidden');
+        }
+    }
+
+    // Update unpaid count
+    const unpaidCount = invoices.filter(inv => !isPaid(inv)).length;
+    const unpaidBadge = document.getElementById('unpaid-badge');
+    if (unpaidBadge) {
+        unpaidBadge.textContent = unpaidCount;
+    }
+}
+
+// ============================================================
+// Toolbar HTML
+// ============================================================
+
+export function injectToolbar() {
+    const container = document.getElementById('invoice-toolbar');
+    if (!container) return;
+
+    container.innerHTML = `
+        <div class="flex flex-wrap items-center gap-3 mb-4 p-4 bg-white rounded-lg shadow-sm border border-gray-200">
+            <!-- Status Filter Buttons -->
+            <div class="flex items-center gap-1 border border-gray-300 rounded-lg p-1 bg-gray-100">
+                <button data-status-filter="all"
+                        onclick="window.invoiceView.setStatus('all')"
+                        class="px-3 py-1.5 text-xs font-medium rounded-md transition-colors bg-white text-gray-600">
+                    All
+                </button>
+                <button data-status-filter="unpaid"
+                        onclick="window.invoiceView.setStatus('unpaid')"
+                        class="px-3 py-1.5 text-xs font-medium rounded-md transition-colors bg-blue-600 text-white">
+                    Unpaid <span id="unpaid-badge" class="ml-1 text-xs opacity-80"></span>
+                </button>
+                <button data-status-filter="paid"
+                        onclick="window.invoiceView.setStatus('paid')"
+                        class="px-3 py-1.5 text-xs font-medium rounded-md transition-colors bg-white text-gray-600">
+                    Paid
+                </button>
+                <button data-status-filter="overdue"
+                        onclick="window.invoiceView.setStatus('overdue')"
+                        class="relative px-3 py-1.5 text-xs font-medium rounded-md transition-colors bg-white text-gray-600">
+                    Overdue
+                    <span id="overdue-badge" class="hidden absolute -top-1.5 -right-1.5 bg-red-500 text-white text-xs rounded-full w-4 h-4 flex items-center justify-center">0</span>
+                </button>
+            </div>
+
+            <div class="w-px h-8 bg-gray-300"></div>
+
+            <!-- Customer Filter -->
+            <div class="flex items-center gap-2">
+                <label class="text-sm font-medium text-gray-700">Customer:</label>
+                <input type="text" id="invoice-filter-customer" placeholder="Filter by name..."
+                       class="px-3 py-1.5 border border-gray-300 rounded-md text-sm w-48 focus:ring-blue-500 focus:border-blue-500">
+            </div>
+
+            <div class="w-px h-8 bg-gray-300"></div>
+
+            <!-- Group By -->
+            <div class="flex items-center gap-2">
+                <label class="text-sm font-medium text-gray-700">Group:</label>
+                <select id="invoice-group-by" class="px-3 py-1.5 border border-gray-300 rounded-md text-sm bg-white focus:ring-blue-500 focus:border-blue-500">
+                    <option value="none">None</option>
+                    <option value="week">Week</option>
+                    <option value="month">Month</option>
+                </select>
+            </div>
+
+            <!-- Invoice Count -->
+            <div class="ml-auto text-sm text-gray-500">
+                <span id="invoice-count" class="font-semibold text-gray-700">0</span> invoices
+            </div>
+        </div>
+    `;
+
+    // Event Listeners
+    document.getElementById('invoice-filter-customer').addEventListener('input', (e) => {
+        filterCustomer = e.target.value;
+        renderInvoiceView();
+    });
+
+    document.getElementById('invoice-group-by').addEventListener('change', (e) => {
+        groupBy = e.target.value;
+        renderInvoiceView();
+    });
+}
+
+// ============================================================
+// Actions
+// ============================================================
+
+export function setStatus(status) {
+    filterStatus = status;
+    renderInvoiceView();
+}
+
+export function viewPDF(id) {
+    window.open(`/api/invoices/${id}/pdf`, '_blank');
+}
+
+export function viewHTML(id) {
+    window.open(`/api/invoices/${id}/html`, '_blank');
+}
+
+export async function exportToQBO(id) {
+    if (!confirm('Rechnung wirklich an QuickBooks Online senden?')) return;
+
+    const btn = event.target;
+    const originalText = btn.textContent;
+    btn.textContent = "⏳...";
+    btn.disabled = true;
+
+    try {
+        const response = await fetch(`/api/invoices/${id}/export`, { method: 'POST' });
+        const result = await response.json();
+
+        if (response.ok) {
+            alert(`✅ Erfolg! QBO ID: ${result.qbo_id}, Rechnungsnr: ${result.qbo_doc_number}`);
+            loadInvoices();
+        } else {
+            alert(`❌ Fehler: ${result.error}`);
+        }
+    } catch (error) {
+        console.error(error);
+        alert('Netzwerkfehler beim Export.');
+    } finally {
+        btn.textContent = originalText;
+        btn.disabled = false;
+    }
+}
+
+export async function markPaid(id) {
+    try {
+        const response = await fetch(`/api/invoices/${id}/mark-paid`, {
+            method: 'PATCH',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ paid_date: new Date().toISOString().split('T')[0] })
+        });
+        if (response.ok) {
+            loadInvoices();
+        } else {
+            const err = await response.json();
+            alert('Error: ' + (err.error || 'Unknown'));
+        }
+    } catch (error) {
+        console.error('Error marking paid:', error);
+    }
+}
+
+export async function markUnpaid(id) {
+    try {
+        const response = await fetch(`/api/invoices/${id}/mark-unpaid`, { method: 'PATCH' });
+        if (response.ok) {
+            loadInvoices();
+        } else {
+            const err = await response.json();
+            alert('Error: ' + (err.error || 'Unknown'));
+        }
+    } catch (error) {
+        console.error('Error marking unpaid:', error);
+    }
+}
+
+export async function edit(id) {
+    if (typeof window.openInvoiceModal === 'function') {
+        await window.openInvoiceModal(id);
+    }
+}
+
+export async function remove(id) {
+    if (!confirm('Are you sure you want to delete this invoice?')) return;
+    try {
+        const response = await fetch(`/api/invoices/${id}`, { method: 'DELETE' });
+        if (response.ok) {
+            loadInvoices();
+        } else {
+            alert('Error deleting invoice');
+        }
+    } catch (error) {
+        console.error('Error:', error);
+    }
+}
+
+// ============================================================
+// Expose to window
+// ============================================================
+
+window.invoiceView = {
+    viewPDF,
+    viewHTML,
+    exportToQBO,
+    markPaid,
+    markUnpaid,
+    edit,
+    remove,
+    loadInvoices,
+    renderInvoiceView,
+    setStatus
+};
\ No newline at end of file
diff --git a/server.js b/server.js
index 5a5b40f..8818e1e 100644
--- a/server.js
+++ b/server.js
@@ -1534,6 +1534,55 @@ app.post('/api/qbo/import-unpaid', async (req, res) => {
     }
 });
 
+// Mark invoice as paid
+app.patch('/api/invoices/:id/mark-paid', async (req, res) => {
+    const { id } = req.params;
+    const { paid_date } = req.body; // Optional: explizites Datum, sonst heute
+    
+    try {
+        const dateToUse = paid_date || new Date().toISOString().split('T')[0];
+        const result = await pool.query(
+            'UPDATE invoices SET paid_date = $1, updated_at = CURRENT_TIMESTAMP WHERE id = $2 RETURNING *',
+            [dateToUse, id]
+        );
+        
+        if (result.rows.length === 0) {
+            return res.status(404).json({ error: 'Invoice not found' });
+        }
+        
+        console.log(`💰 Invoice #${result.rows[0].invoice_number} als bezahlt markiert (${dateToUse})`);
+        res.json(result.rows[0]);
+    } catch (error) {
+        console.error('Error marking invoice as paid:', error);
+        res.status(500).json({ error: 'Error marking invoice as paid' });
+    }
+});
+
+// Mark invoice as unpaid
+app.patch('/api/invoices/:id/mark-unpaid', async (req, res) => {
+    const { id } = req.params;
+    
+    try {
+        const result = await pool.query(
+            'UPDATE invoices SET paid_date = NULL, updated_at = CURRENT_TIMESTAMP WHERE id = $1 RETURNING *',
+            [id]
+        );
+        
+        if (result.rows.length === 0) {
+            return res.status(404).json({ error: 'Invoice not found' });
+        }
+        
+        console.log(`↩️ Invoice #${result.rows[0].invoice_number} als unbezahlt markiert`);
+        res.json(result.rows[0]);
+    } catch (error) {
+        console.error('Error marking invoice as unpaid:', error);
+        res.status(500).json({ error: 'Error marking invoice as unpaid' });
+    }
+});
+
+
+
+
 
 
 // Start server and browser
diff --git a/templates/invoice-template.html b/templates/invoice-template.html
index f132d72..474d9f5 100644
--- a/templates/invoice-template.html
+++ b/templates/invoice-template.html
@@ -86,7 +86,11 @@
             font-size: 14px;
             line-height: 1.5;
         }
-        
+        .info-div {
+            display: flex;
+            height: fit-content;
+            margin-top: auto;
+        }
         .info-table {
             border-collapse: collapse;
             font-size: 13px;
@@ -110,7 +114,7 @@
         .items-table {
             width: 100%;
             border-collapse: collapse;
-            margin: 20px 0;
+            margin: 40px 0 20px 0;
             font-size: 13px;
         }
         
@@ -238,24 +242,26 @@
                     {{CUSTOMER_CITY}}, {{CUSTOMER_STATE}} {{CUSTOMER_ZIP}}
                 </div>
             </div>
-            <table class="info-table">
-                <thead>
-                    <tr>
-                        <th>INVOICE #</th>
-                        <th>ACCOUNT NO.</th>
-                        <th>DATE</th>
-                        <th>TERMS</th>
-                    </tr>
-                </thead>
-                <tbody>
-                    <tr>
-                        <td>{{INVOICE_NUMBER}}</td>
-                        <td>{{ACCOUNT_NUMBER}}</td>
-                        <td>{{INVOICE_DATE}}</td>
-                        <td>{{TERMS}}</td>
-                    </tr>
-                </tbody>
-            </table>
+            <div class="info-div">
+                <table class="info-table">
+                    <thead>
+                        <tr>
+                            <th>INVOICE #</th>
+                            <th>ACCOUNT NO.</th>
+                            <th>DATE</th>
+                            <th>TERMS</th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        <tr>
+                            <td>{{INVOICE_NUMBER}}</td>
+                            <td>{{ACCOUNT_NUMBER}}</td>
+                            <td>{{INVOICE_DATE}}</td>
+                            <td>{{TERMS}}</td>
+                        </tr>
+                    </tbody>
+                </table>
+            </div>
         </div>
         
         {{AUTHORIZATION}}