diff --git a/InvenTree/part/bom.py b/InvenTree/part/bom.py
index fe973efaf0..b0ba1a5dae 100644
--- a/InvenTree/part/bom.py
+++ b/InvenTree/part/bom.py
@@ -46,14 +46,19 @@ class BomUploadManager:
     """ Class for managing an uploaded BOM file """
 
     # Fields which are absolutely necessary for valid upload
-    HEADERS = [
+    REQUIRED_HEADERS = [
         'Part',
-        'Quantity',
+        'Quantity'
+    ]
+    
+    OPTIONAL_HEADERS = [
         'Reference',
         'Overage',
         'Notes'
     ]
 
+    HEADERS = REQUIRED_HEADERS + OPTIONAL_HEADERS
+
     def __init__(self, bom_file):
         """ Initialize the BomUpload class with a user-uploaded file object """
         
diff --git a/InvenTree/part/templates/part/bom_upload/select_fields.html b/InvenTree/part/templates/part/bom_upload/select_fields.html
index d06846b33d..6bb6223dba 100644
--- a/InvenTree/part/templates/part/bom_upload/select_fields.html
+++ b/InvenTree/part/templates/part/bom_upload/select_fields.html
@@ -5,6 +5,17 @@
 
 <h4>Step 2 of 3 - Select BOM Fields</h4>
 
+{% if missing and missing|length > 0 %}
+<div class='alert alert-danger alert-block' role='alert'>
+    Missing selections for the following columns:
+    <ul>
+        {% for col in missing %}
+        <li>{{ col }}</li>
+        {% endfor %}
+    </ul>
+</div>
+{% endif %}
+
 <form method="post" action='' class='js-modal-form' enctype="multipart/form-data">
     {% csrf_token %}
     {% load crispy_forms_tags %}
@@ -25,6 +36,9 @@
                         <option value='{{ req }}'{% if req == col.guess %}selected='selected'{% endif %}>{{ req }}</option>
                         {% endfor %}
                     </select>
+                    {% if col.duplicate %}
+                    <p class='help-inline'>Duplicate column selection</p>
+                    {% endif %}
                     <input type='hidden' name='col_name_{{ forloop.counter0 }}' value='{{ col.name }}'/>
                     {{ col.name }}
                 </th>
diff --git a/InvenTree/part/views.py b/InvenTree/part/views.py
index abd787bc5c..1c90a54752 100644
--- a/InvenTree/part/views.py
+++ b/InvenTree/part/views.py
@@ -752,13 +752,11 @@ class BomUpload(AjaxView, FormMixin):
 
         for item in self.request.POST:
 
-            print(item)
-
             value = self.request.POST[item]
 
             # Extract the column names
             if item.startswith('col_name_'):
-                col_id = item.replace('col_name_', '')
+                col_id = int(item.replace('col_name_', ''))
                 col_name = value
 
                 column_names[col_id] = col_name
@@ -766,7 +764,7 @@ class BomUpload(AjaxView, FormMixin):
             # Extract the column selections
             if item.startswith('col_select_'):
 
-                col_id = item.replace('col_select_', '')
+                col_id = int(item.replace('col_select_', ''))
                 col_name = value
 
                 column_selections[col_id] = value
@@ -779,17 +777,49 @@ class BomUpload(AjaxView, FormMixin):
                 if len(s) < 4:
                     continue
 
-                row_id = s[1]
-                col_id = s[3]
+                row_id = int(s[1])
+                col_id = int(s[3])
                 
                 if not row_id in row_data:
                     row_data[row_id] = {}
 
                 row_data[row_id][col_id] = value
-                
+
+        col_ids = sorted(column_names.keys())
+
+        headers = []
+
+        for col in col_ids:
+            if col not in column_selections:
+                continue
+
+            header = ({
+                'name': column_names[col],
+                'guess': column_selections[col]
+            })
+
+            # Duplicate guess?
+            guess = column_selections[col]
+
+            if guess:
+                n = list(column_selections.values()).count(column_selections[col])
+                if n > 1:
+                    header['duplicate'] = True
+
+            headers.append(header)
+
+        # Are there any missing columns?
+        missing = []
+
+        for col in BomUploadManager.REQUIRED_HEADERS:
+            if not col in column_selections.values():
+                missing.append(col)
+
         ctx = {
             # The headers that we know about
-            'known_headers': BomUploadManager.HEADERS,
+            'req_cols': BomUploadManager.HEADERS,
+            'bom_cols': headers,
+            'missing': missing,
         }
 
         return self.renderJsonResponse(self.request, form=self.get_form(), data=data, context=ctx)