diff --git a/public/app.js b/public/app.js
index 7f20945..b0e4da8 100644
--- a/public/app.js
+++ b/public/app.js
@@ -709,6 +709,16 @@ async function convertQuoteToInvoice(quoteId) {
 }
 
 // Invoice Management - Same accordion pattern
+async function fetchNextInvoiceNumber() {
+    try {
+        const response = await fetch('/api/invoices/next-number');
+        const data = await response.json();
+        document.getElementById('invoice-number').value = data.next_number;
+    } catch (error) {
+        console.error('Error fetching next invoice number:', error);
+    }
+}
+
 async function loadInvoices() {
     try {
         const response = await fetch('/api/invoices');
@@ -765,6 +775,7 @@ async function openInvoiceModal(invoiceId = null) {
             }
         }
         
+        document.getElementById('invoice-number').value = data.invoice.invoice_number;
         document.getElementById('invoice-customer').value = data.invoice.customer_id;
         const dateOnly = data.invoice.invoice_date.split('T')[0];
         document.getElementById('invoice-date').value = dateOnly;
@@ -788,6 +799,9 @@ async function openInvoiceModal(invoiceId = null) {
         itemCounter = 0;
         setDefaultDate();
         
+        // Fetch next invoice number
+        fetchNextInvoiceNumber();
+        
         // Add one default item
         addInvoiceItem();
     }
@@ -1037,7 +1051,15 @@ async function handleInvoiceSubmit(e) {
         return;
     }
     
+    const invoiceNumber = document.getElementById('invoice-number').value;
+    
+    if (!invoiceNumber || !/^\d+$/.test(invoiceNumber)) {
+        alert('Invalid invoice number. Must be a numeric value.');
+        return;
+    }
+    
     const data = {
+        invoice_number: invoiceNumber,
         customer_id: parseInt(document.getElementById('invoice-customer').value),
         invoice_date: document.getElementById('invoice-date').value,
         terms: document.getElementById('invoice-terms').value,
@@ -1060,7 +1082,8 @@ async function handleInvoiceSubmit(e) {
             closeInvoiceModal();
             loadInvoices();
         } else {
-            alert('Error saving invoice');
+            const error = await response.json();
+            alert(error.error || 'Error saving invoice');
         }
     } catch (error) {
         console.error('Error:', error);
@@ -1090,4 +1113,4 @@ async function deleteInvoice(id) {
 
 function viewInvoicePDF(id) {
     window.open(`/api/invoices/${id}/pdf`, '_blank');
-}
+}
\ No newline at end of file
diff --git a/public/index.html b/public/index.html
index a8d2d6f..1e985d5 100644
--- a/public/index.html
+++ b/public/index.html
@@ -335,7 +335,13 @@
             </div>
             
             <form id="invoice-form" class="space-y-6">
-                <div class="grid grid-cols-4 gap-4">
+                <div class="grid grid-cols-5 gap-4">
+                    <div>
+                        <label class="block text-sm font-medium text-gray-700 mb-1">Invoice #</label>
+                        <input type="text" id="invoice-number" required pattern="[0-9]+" 
+                               class="w-full px-4 py-2 border border-gray-300 rounded-md focus:ring-blue-500 focus:border-blue-500"
+                               title="Must be a numeric value">
+                    </div>
                     <div x-data="customerSearch('invoice')" class="relative">
                         <label class="block text-sm font-medium text-gray-700 mb-1">Customer</label>
                         <div class="relative">
diff --git a/server.js b/server.js
index 61d3265..a41c61c 100644
--- a/server.js
+++ b/server.js
@@ -108,19 +108,15 @@ async function getNextQuoteNumber() {
 }
 
 async function getNextInvoiceNumber() {
-    const year = new Date().getFullYear();
     const result = await pool.query(
-        'SELECT invoice_number FROM invoices WHERE invoice_number LIKE $1 ORDER BY invoice_number DESC LIMIT 1',
-        [`${year}-%`]
+        'SELECT MAX(CAST(invoice_number AS INTEGER)) as max_number FROM invoices WHERE invoice_number ~ \'^[0-9]+$\''
     );
     
-    if (result.rows.length === 0) {
-        return `${year}-001`;
+    if (result.rows.length === 0 || result.rows[0].max_number === null) {
+        return '110508';
     }
     
-    const lastNumber = parseInt(result.rows[0].invoice_number.split('-')[1]);
-    const nextNumber = String(lastNumber + 1).padStart(3, '0');
-    return `${year}-${nextNumber}`;
+    return String(parseInt(result.rows[0].max_number) + 1);
 }
 
 // Logo endpoints
@@ -419,14 +415,40 @@ app.get('/api/invoices/:id', async (req, res) => {
     }
 });
 
+// New endpoint to get next invoice number
+app.get('/api/invoices/next-number', async (req, res) => {
+    try {
+        const nextNumber = await getNextInvoiceNumber();
+        res.json({ next_number: nextNumber });
+    } catch (error) {
+        console.error('Error getting next invoice number:', error);
+        res.status(500).json({ error: 'Error getting next invoice number' });
+    }
+});
+
 app.post('/api/invoices', async (req, res) => {
-    const { customer_id, invoice_date, terms, auth_code, tax_exempt, items, created_from_quote_id } = req.body;
+    const { invoice_number, customer_id, invoice_date, terms, auth_code, tax_exempt, items, created_from_quote_id } = req.body;
     
     const client = await pool.connect();
     try {
         await client.query('BEGIN');
         
-        const invoice_number = await getNextInvoiceNumber();
+        // Validate invoice_number is provided and is numeric
+        if (!invoice_number || !/^\d+$/.test(invoice_number)) {
+            await client.query('ROLLBACK');
+            return res.status(400).json({ error: 'Invalid invoice number. Must be a numeric value.' });
+        }
+        
+        // Check if invoice number already exists
+        const existingInvoice = await client.query(
+            'SELECT id FROM invoices WHERE invoice_number = $1',
+            [invoice_number]
+        );
+        
+        if (existingInvoice.rows.length > 0) {
+            await client.query('ROLLBACK');
+            return res.status(400).json({ error: `Invoice number ${invoice_number} already exists.` });
+        }
         
         let subtotal = 0;
         
@@ -534,12 +556,29 @@ app.post('/api/quotes/:id/convert-to-invoice', async (req, res) => {
 
 app.put('/api/invoices/:id', async (req, res) => {
     const { id } = req.params;
-    const { customer_id, invoice_date, terms, auth_code, tax_exempt, items } = req.body;
+    const { invoice_number, customer_id, invoice_date, terms, auth_code, tax_exempt, items } = req.body;
     
     const client = await pool.connect();
     try {
         await client.query('BEGIN');
         
+        // Validate invoice_number is provided and is numeric
+        if (!invoice_number || !/^\d+$/.test(invoice_number)) {
+            await client.query('ROLLBACK');
+            return res.status(400).json({ error: 'Invalid invoice number. Must be a numeric value.' });
+        }
+        
+        // Check if invoice number already exists (excluding current invoice)
+        const existingInvoice = await client.query(
+            'SELECT id FROM invoices WHERE invoice_number = $1 AND id != $2',
+            [invoice_number, id]
+        );
+        
+        if (existingInvoice.rows.length > 0) {
+            await client.query('ROLLBACK');
+            return res.status(400).json({ error: `Invoice number ${invoice_number} already exists.` });
+        }
+        
         let subtotal = 0;
         
         for (const item of items) {
@@ -554,10 +593,10 @@ app.put('/api/invoices/:id', async (req, res) => {
         const total = subtotal + tax_amount;
         
         await client.query(
-            `UPDATE invoices SET customer_id = $1, invoice_date = $2, terms = $3, auth_code = $4, tax_exempt = $5, 
-             tax_rate = $6, subtotal = $7, tax_amount = $8, total = $9, updated_at = CURRENT_TIMESTAMP
-             WHERE id = $10`,
-            [customer_id, invoice_date, terms, auth_code, tax_exempt, tax_rate, subtotal, tax_amount, total, id]
+            `UPDATE invoices SET invoice_number = $1, customer_id = $2, invoice_date = $3, terms = $4, auth_code = $5, tax_exempt = $6, 
+             tax_rate = $7, subtotal = $8, tax_amount = $9, total = $10, updated_at = CURRENT_TIMESTAMP
+             WHERE id = $11`,
+            [invoice_number, customer_id, invoice_date, terms, auth_code, tax_exempt, tax_rate, subtotal, tax_amount, total, id]
         );
         
         await client.query('DELETE FROM invoice_items WHERE invoice_id = $1', [id]);
@@ -598,6 +637,8 @@ app.delete('/api/invoices/:id', async (req, res) => {
     }
 });
 
+// PDF Generation code continues below...
+
 // PDF Generation using templates and persistent browser
 app.get('/api/quotes/:id/pdf', async (req, res) => {
     const { id } = req.params;
@@ -858,8 +899,6 @@ app.get('/api/invoices/:id/pdf', async (req, res) => {
 });
 
 
-// Nach den PDF-Endpoints, vor "Start server", einfügen:
-
 // HTML Debug Endpoints
 app.get('/api/quotes/:id/html', async (req, res) => {
     const { id } = req.params;
diff --git a/templates/invoice-template.html b/templates/invoice-template.html
index f23791a..f132d72 100644
--- a/templates/invoice-template.html
+++ b/templates/invoice-template.html
@@ -26,7 +26,7 @@
             display: flex;
             justify-content: space-between;
             align-items: flex-start;
-            margin-bottom: 40px;
+            margin-bottom: 20px;
             padding-bottom: 20px;
             border-bottom: 2px solid #333;
             position: relative;
@@ -70,7 +70,7 @@
         .bill-to-section {
             display: flex;
             justify-content: space-between;
-            margin: 30px 0 40px 0;
+            margin: 0px 0 20px 0;
         }
         
         .bill-to {
@@ -166,7 +166,7 @@
         .items-table td.rate,
         .items-table td.amount {
             text-align: right;
-            width: 100px;
+            width: 70px;
         }
         
         .footer-row td {
@@ -220,11 +220,9 @@
                     <em>Providing IT Services and Support in South Texas Since 1996</em>
                 </div>
                 <div class="contact-info">
-                    Phone:<br>
                     (361) 765-8400<br>
                     (361) 765-8401<br>
                     (361) 232-6578<br>
-                    Email:<br>
                     accounting@bayarea-cc.com
                 </div>
             </div>
diff --git a/templates/quote-template.html b/templates/quote-template.html
index feb9ce4..312ccaa 100644
--- a/templates/quote-template.html
+++ b/templates/quote-template.html
@@ -26,7 +26,7 @@
             display: flex;
             justify-content: space-between;
             align-items: flex-start;
-            margin-bottom: 40px;
+            margin-bottom: 20px;
             padding-bottom: 20px;
             border-bottom: 2px solid #333;
             position: relative;
@@ -70,7 +70,7 @@
         .bill-to-section {
             display: flex;
             justify-content: space-between;
-            margin: 30px 0 60px 0;
+            margin: 0px 0 20px 0;
         }
         
         .bill-to {
@@ -166,7 +166,7 @@
         .items-table td.rate,
         .items-table td.amount {
             text-align: right;
-            width: 100px;
+            width: 70px;
         }
         
         .footer-row td {
@@ -220,11 +220,9 @@
                     <em>Providing IT Services and Support in South Texas Since 1996</em>
                 </div>
                 <div class="contact-info">
-                    Phone:<br>
                     (361) 765-8400<br>
                     (361) 765-8401<br>
                     (361) 232-6578<br>
-                    Email:<br>
                     support@bayarea-cc.com
                 </div>
             </div>