diff --git a/src/wireviz/Harness.py b/src/wireviz/Harness.py
index 50b180b..0c15b49 100644
--- a/src/wireviz/Harness.py
+++ b/src/wireviz/Harness.py
@@ -349,7 +349,7 @@ class Harness:
             conn_color = f', {shared.color}' if shared.color else ''
             name = f'Connector{conn_type}{conn_subtype}{conn_pincount}{conn_color}'
             item = {'item': name, 'qty': len(designators), 'unit': '', 'designators': designators if shared.show_name else '',
-                    'manufacturer': shared.manufacturer, 'manufacturer part number': shared.mpn, 'part number': shared.pn}
+                    'manufacturer': shared.manufacturer, 'mpn': shared.mpn, 'pn': shared.pn}
             bom_connectors.append(item)
             bom_connectors = sorted(bom_connectors, key=lambda k: k['item'])  # https://stackoverflow.com/a/73050
         bom.extend(bom_connectors)
@@ -368,7 +368,7 @@ class Harness:
             shield_name = ' shielded' if shared.shield else ''
             name = f'Cable{cable_type}, {shared.wirecount}{gauge_name}{shield_name}'
             item = {'item': name, 'qty': round(total_length, 3), 'unit': 'm', 'designators': designators,
-                    'manufacturer': shared.manufacturer, 'manufacturer part number': shared.mpn, 'part number': shared.pn}
+                    'manufacturer': shared.manufacturer, 'mpn': shared.mpn, 'pn': shared.pn}
             bom_cables.append(item)
         # bundles (ignores wirecount)
         wirelist = []
@@ -379,10 +379,10 @@ class Harness:
                 for index, color in enumerate(bundle.colors, 0):
                     wirelist.append({'type': bundle.type, 'gauge': bundle.gauge, 'gauge_unit': bundle.gauge_unit, 'length': bundle.length, 'color': color, 'designator': bundle.name,
                                      'manufacturer': index_if_list(bundle.manufacturer, index),
-                                     'manufacturer part number': index_if_list(bundle.mpn, index),
-                                     'part number': index_if_list(bundle.pn, index)})
+                                     'mpn': index_if_list(bundle.mpn, index),
+                                     'pn': index_if_list(bundle.pn, index)})
         # join similar wires from all the bundles to a single BOM item
-        wire_group = lambda w: (w.get('type', None), w['gauge'], w['gauge_unit'], w['color'], w['manufacturer'], w['manufacturer part number'], w['part number'])
+        wire_group = lambda w: (w.get('type', None), w['gauge'], w['gauge_unit'], w['color'], w['manufacturer'], w['mpn'], w['pn'])
         for group in Counter([wire_group(v) for v in wirelist]):
             items = [v for v in wirelist if wire_group(v) == group]
             shared = items[0]
@@ -395,7 +395,7 @@ class Harness:
             gauge_color = f', {shared["color"]}' if 'color' in shared != '' else ''
             name = f'Wire{wire_type}{gauge_name}{gauge_color}'
             item = {'item': name, 'qty': round(total_length, 3), 'unit': 'm', 'designators': designators,
-                    'manufacturer': shared['manufacturer'], 'manufacturer part number': shared['manufacturer part number'], 'part number': shared['part number']}
+                    'manufacturer': shared['manufacturer'], 'mpn': shared['mpn'], 'pn': shared['pn']}
             bom_cables.append(item)
             bom_cables = sorted(bom_cables, key=lambda k: k['item'])  # sort list of dicts by their values (https://stackoverflow.com/a/73050)
         bom.extend(bom_cables)
@@ -405,7 +405,7 @@ class Harness:
             if isinstance(item.get('designators', None), List):
                 item['designators'].sort()  # sort designators if a list is provided
             item = {'item': name, 'qty': item.get('qty', None), 'unit': item.get('unit', None), 'designators': item.get('designators', None),
-                    'manufacturer': item.get('manufacturer', None), 'manufacturer part number': item.get('mpn', None), 'part number': item.get('pn', None)}
+                    'manufacturer': item.get('manufacturer', None), 'mpn': item.get('mpn', None), 'pn': item.get('pn', None)}
             bom_extra.append(item)
         bom_extra = sorted(bom_extra, key=lambda k: k['item'])
         bom.extend(bom_extra)
@@ -414,11 +414,16 @@ class Harness:
     def bom_list(self):
         bom = self.bom()
         keys = ['item', 'qty', 'unit', 'designators'] # these BOM columns will always be included
-        for fieldname in ['part number', 'manufacturer', 'manufacturer part number']: # these optional BOM columns will only be included if at least one BOM item actually uses them
+        for fieldname in ['pn', 'manufacturer', 'mpn']: # these optional BOM columns will only be included if at least one BOM item actually uses them
             if any(fieldname in x and x.get(fieldname, None) for x in bom):
                 keys.append(fieldname)
         bom_list = []
-        bom_list.append([k.capitalize() for k in keys])  # create header row with keys
+        # list of staic bom header names,  headers not specified here are generated by capitilising the internal name
+        bom_headings = {
+            "pn": "P/N",
+            "mpn": "MPN"
+        }
+        bom_list.append([(bom_headings[k] if k in bom_headings else k.capitalize()) for k in keys])  # create header row with keys
         for item in bom:
             item_list = [item.get(key, '') for key in keys]  # fill missing values with blanks
             item_list = [', '.join(subitem) if isinstance(subitem, List) else subitem for subitem in item_list]  # convert any lists into comma separated strings