diff --git a/samples/invoices.csv b/samples/invoices.csv
new file mode 100644
index 0000000..c6e93e8
--- /dev/null
+++ b/samples/invoices.csv
@@ -0,0 +1,6 @@
+InvoiceId;CustomerId;Amount;Currency
+INV-001;C-100;125.50;EUR
+INV-002;;89.00;EUR
+INV-003;C-300;abc;EUR
+INV-004;C-400;-10.00;EUR
+;;0;EUR
diff --git a/src/ImportAssist.Cli/Program.cs b/src/ImportAssist.Cli/Program.cs
index 29f42d7..bd3d151 100644
--- a/src/ImportAssist.Cli/Program.cs
+++ b/src/ImportAssist.Cli/Program.cs
@@ -1,13 +1,54 @@
 using ImportAssist.Core;
 
-InvoiceRow[] rows =
-[
-    new("INV-001", "C-100", "125.50", "EUR"),
-    new("INV-002", "",      "89.00",  "EUR"),
-    new("INV-003", "C-300", "abc",    "EUR"),
-    new("INV-004", "C-400", "-10.00", "EUR"),
-    new("",        "",      "0",      "EUR")
-];
+if (args.Length != 1)
+{
+    Console.Error.WriteLine(
+        "Bitte den Pfad zur CSV-Datei als Argument angeben.");
+    Environment.ExitCode = 1;
+    return;
+}
+
+var path = args[0];
+
+if (!File.Exists(path))
+{
+    Console.Error.WriteLine($"Datei nicht gefunden: {path}");
+    Environment.ExitCode = 1;
+    return;
+}
+
+var lines = File.ReadAllLines(path);
+
+if (lines.Length == 0 ||
+    lines[0] != "InvoiceId;CustomerId;Amount;Currency")
+{
+    Console.Error.WriteLine(
+        "Die Datei ist leer oder die Kopfzeile stimmt nicht.");
+    Environment.ExitCode = 1;
+    return;
+}
+
+var rows = new List<InvoiceRow>();
+
+for (var index = 1; index < lines.Length; index++)
+{
+    var line = lines[index];
+    var columns = line.Split(';');
+
+    if (line.Contains('"') || columns.Length != 4)
+    {
+        Console.Error.WriteLine(
+            $"Zeile {index + 1}: Erwartet werden vier Spalten ohne Anführungszeichen.");
+        Environment.ExitCode = 1;
+        return;
+    }
+
+    rows.Add(new InvoiceRow(
+        columns[0],
+        columns[1],
+        columns[2],
+        columns[3]));
+}
 
 foreach (var row in rows)
 {