diff --git a/invoice_edit_modal.php b/invoice_edit_modal.php
index f98cf7cc..38878590 100644
--- a/invoice_edit_modal.php
+++ b/invoice_edit_modal.php
@@ -1,80 +1,92 @@
 <div class="modal" id="editInvoiceModal<?php echo $invoice_id; ?>" tabindex="-1">
-  <div class="modal-dialog">
-    <div class="modal-content bg-dark">
-      <div class="modal-header">
-        <h5 class="modal-title"><i class="fas fa-fw fa-file-invoice mr-2"></i>Editing invoice: <strong><?php echo "$invoice_prefix$invoice_number"; ?></strong> - <?php echo $client_name; ?></h5>
-        <button type="button" class="close text-white" data-dismiss="modal">
-          <span>&times;</span>
-        </button>
-      </div>
-      <form action="post.php" method="post" autocomplete="off">
-        <input type="hidden" name="invoice_id" value="<?php echo $invoice_id; ?>">
-
-        <div class="modal-body bg-white">
-
-          <div class="form-group">
-            <label>Invoice Date <strong class="text-danger">*</strong></label>
-            <div class="input-group">
-              <div class="input-group-prepend">
-                <span class="input-group-text"><i class="fa fa-fw fa-calendar"></i></span>
-              </div>
-              <input type="date" class="form-control" name="date" max="2999-12-31" value="<?php echo $invoice_date; ?>" required>
+    <div class="modal-dialog">
+        <div class="modal-content bg-dark">
+            <div class="modal-header">
+                <h5 class="modal-title"><i class="fas fa-fw fa-file-invoice mr-2"></i>Editing invoice: <strong><?php echo "$invoice_prefix$invoice_number"; ?></strong> - <?php echo $client_name; ?></h5>
+                <button type="button" class="close text-white" data-dismiss="modal">
+                    <span>&times;</span>
+                </button>
             </div>
-          </div>
+            <form action="post.php" method="post" autocomplete="off">
+                <input type="hidden" name="invoice_id" value="<?php echo $invoice_id; ?>">
 
-          <div class="form-group">
-            <label>Invoice Due <strong class="text-danger">*</strong></label>
-            <div class="input-group">
-              <div class="input-group-prepend">
-                <span class="input-group-text"><i class="fa fa-fw fa-calendar-alt"></i></span>
-              </div>
-              <input type="date" class="form-control" name="due" max="2999-12-31" value="<?php echo $invoice_due; ?>" required>
-            </div>
-          </div>
+                <div class="modal-body bg-white">
 
-          <div class="form-group">
-            <label>Income Category <strong class="text-danger">*</strong></label>
-            <div class="input-group">
-              <div class="input-group-prepend">
-                <span class="input-group-text"><i class="fa fa-fw fa-tag"></i></span>
-              </div>
-              <select class="form-control select2" name="category" required>
-                <option value="">- Category -</option>
-                <?php 
-                
-                $sql_income_category = mysqli_query($mysqli, "SELECT * FROM categories WHERE category_type = 'Income' AND (category_archived_at > '$invoice_created_at' OR category_archived_at IS NULL) ORDER BY category_name ASC"); 
-                while ($row = mysqli_fetch_array($sql_income_category)) {
-                  $category_id_select= intval($row['category_id']);
-                  $category_name_select = nullable_htmlentities($row['category_name']);
-                ?>
-                <option <?php if ($category_id == $category_id_select) { echo "selected"; } ?> value="<?php echo $category_id_select; ?>"><?php echo $category_name_select; ?></option>
-                
-                <?php
-                }
-                ?>
-              </select>
-              <div class="input-group-append">
-                <button type="button" class="btn btn-secondary" data-toggle="modal" data-target="#addQuickCategoryIncomeModal"><i class="fas fa-fw fa-plus"></i></button>
-              </div>
-            </div>
-          </div>
+                    <div class="form-group">
+                        <label>Invoice Date <strong class="text-danger">*</strong></label>
+                        <div class="input-group">
+                            <div class="input-group-prepend">
+                                <span class="input-group-text"><i class="fa fa-fw fa-calendar"></i></span>
+                            </div>
+                            <input type="date" class="form-control" name="date" max="2999-12-31" value="<?php echo $invoice_date; ?>" required>
+                        </div>
+                    </div>
 
-          <div class="form-group">
-            <label>Scope</label>
-            <div class="input-group">
-              <div class="input-group-prepend">
-                <span class="input-group-text"><i class="fa fa-fw fa-comment"></i></span>
-              </div>
-              <input type="text" class="form-control" name="scope" placeholder="Quick description" value="<?php echo $invoice_scope; ?>">
-            </div>
-          </div>
+                    <div class="form-group">
+                        <label>Invoice Due <strong class="text-danger">*</strong></label>
+                        <div class="input-group">
+                            <div class="input-group-prepend">
+                                <span class="input-group-text"><i class="fa fa-fw fa-calendar-alt"></i></span>
+                            </div>
+                            <input type="date" class="form-control" name="due" max="2999-12-31" value="<?php echo $invoice_due; ?>" required>
+                        </div>
+                    </div>
 
+                    <div class="form-group">
+                        <label>Income Category <strong class="text-danger">*</strong></label>
+                        <div class="input-group">
+                            <div class="input-group-prepend">
+                                <span class="input-group-text"><i class="fa fa-fw fa-tag"></i></span>
+                            </div>
+                            <select class="form-control select2" name="category" required>
+                                <option value="">- Category -</option>
+                                <?php
+
+                                $sql_income_category = mysqli_query($mysqli, "SELECT * FROM categories WHERE category_type = 'Income' AND (category_archived_at > '$invoice_created_at' OR category_archived_at IS NULL) ORDER BY category_name ASC");
+                                while ($row = mysqli_fetch_array($sql_income_category)) {
+                                    $category_id_select = intval($row['category_id']);
+                                    $category_name_select = nullable_htmlentities($row['category_name']);
+                                ?>
+                                    <option <?php if ($category_id == $category_id_select) {
+                                                echo "selected";
+                                            } ?> value="<?php echo $category_id_select; ?>"><?php echo $category_name_select; ?></option>
+
+                                <?php
+                                }
+                                ?>
+                            </select>
+                            <div class="input-group-append">
+                                <button type="button" class="btn btn-secondary" data-toggle="modal" data-target="#addQuickCategoryIncomeModal"><i class="fas fa-fw fa-plus"></i></button>
+                            </div>
+                        </div>
+                    </div>
+
+                    <div class='form-group'>
+                        <label>Discount Amount</label>
+                        <div class='input-group'>
+                            <div class='input-group-prepend'>
+                                <span class='input-group-text'><i class='fa fa-fw fa-dollar-sign'></i></span>
+                            </div>
+                            <input type='number' class='form-control' name='invoice_discount' placeholder='Discount Amount' value='<?php echo $invoice_discount; ?>'>
+                        </div>
+                    </div>
+
+                    <div class="form-group">
+                        <label>Scope</label>
+                        <div class="input-group">
+                            <div class="input-group-prepend">
+                                <span class="input-group-text"><i class="fa fa-fw fa-comment"></i></span>
+                            </div>
+                            <input type="text" class="form-control" name="scope" placeholder="Quick description" value="<?php echo $invoice_scope; ?>">
+                        </div>
+                    </div>
+
+                </div>
+                <div class="modal-footer bg-white">
+                    <button type="submit" name="edit_invoice" class="btn btn-primary text-bold"><i class="fas fa-check mr-2"></i>Save</button>
+                    <button type="button" class="btn btn-light" data-dismiss="modal"><i class="fa fa-times mr-2"></i>Cancel</button>
+                </div>
+            </form>
         </div>
-        <div class="modal-footer bg-white">
-          <button type="submit" name="edit_invoice" class="btn btn-primary text-bold"><i class="fas fa-check mr-2"></i>Save</button>
-          <button type="button" class="btn btn-light" data-dismiss="modal"><i class="fa fa-times mr-2"></i>Cancel</button>
-        </div>
-      </form>
     </div>
-  </div>
 </div>
\ No newline at end of file