diff --git a/InvenTree/build/api.py b/InvenTree/build/api.py
index e6331f2b6a..10cc7e2024 100644
--- a/InvenTree/build/api.py
+++ b/InvenTree/build/api.py
@@ -11,7 +11,7 @@ from rest_framework import generics
 
 from django.conf.urls import url, include
 
-from InvenTree.helpers import str2bool
+from InvenTree.helpers import str2bool, isNull
 from InvenTree.status_codes import BuildStatus
 
 from .models import Build, BuildItem
@@ -194,7 +194,11 @@ class BuildItemList(generics.ListCreateAPIView):
         output = params.get('output', None)
 
         if output:
-            queryset = queryset.filter(install_into=output)
+
+            if isNull(output):
+                queryset = queryset.filter(install_into=None)
+            else:
+                queryset = queryset.filter(install_into=output)
 
         return queryset
 
diff --git a/InvenTree/build/forms.py b/InvenTree/build/forms.py
index 0726779b87..d4f5e23ce7 100644
--- a/InvenTree/build/forms.py
+++ b/InvenTree/build/forms.py
@@ -165,16 +165,10 @@ class AutoAllocateForm(HelperForm):
 
     confirm = forms.BooleanField(required=True, label=_('Confirm'), help_text=_('Confirm stock allocation'))
 
-    # Keep track of which build output we are interested in
-    output = forms.ModelChoiceField(
-        queryset=StockItem.objects.all(),
-    )
-
     class Meta:
         model = Build
         fields = [
             'confirm',
-            'output',
         ]
 
 
diff --git a/InvenTree/build/models.py b/InvenTree/build/models.py
index 5a23752071..0fc92ce045 100644
--- a/InvenTree/build/models.py
+++ b/InvenTree/build/models.py
@@ -489,7 +489,7 @@ class Build(MPTTModel):
         self.status = BuildStatus.CANCELLED
         self.save()
 
-    def getAutoAllocations(self, output):
+    def getAutoAllocations(self):
         """
         Return a list of StockItem objects which will be allocated
         using the 'AutoAllocate' function.
@@ -521,15 +521,19 @@ class Build(MPTTModel):
 
             part = bom_item.sub_part
 
+            # If the part is "trackable" it cannot be auto-allocated
+            if part.trackable:
+                continue
+
             # Skip any parts which are already fully allocated
-            if self.isPartFullyAllocated(part, output):
+            if self.isPartFullyAllocated(part, None):
                 continue
 
             # How many parts are required to complete the output?
-            required = self.unallocatedQuantity(part, output)
+            required = self.unallocatedQuantity(part, None)
 
             # Grab a list of stock items which are available
-            stock_items = self.availableStockItems(part, output)
+            stock_items = self.availableStockItems(part, None)
 
             # Ensure that the available stock items are in the correct location
             if self.take_from is not None:
@@ -544,7 +548,6 @@ class Build(MPTTModel):
                 build_items = BuildItem.objects.filter(
                     build=self,
                     stock_item=stock_item,
-                    install_into=output
                 )
 
                 if len(build_items) > 0:
@@ -567,24 +570,45 @@ class Build(MPTTModel):
         return allocations
 
     @transaction.atomic
-    def unallocateStock(self, output=None, part=None):
+    def unallocateOutput(self, output, part=None):
         """
-        Deletes all stock allocations for this build.
-        
-        Args:
-            output: Specify which build output to delete allocations (optional)
-
+        Unallocate all stock which are allocated against the provided "output" (StockItem)
         """
 
-        allocations = BuildItem.objects.filter(build=self.pk)
-
-        if output:
-            allocations = allocations.filter(install_into=output.pk)
+        allocations = BuildItem.objects.filter(
+            build=self,
+            install_into=output
+        )
 
         if part:
             allocations = allocations.filter(stock_item__part=part)
 
-        # Remove all the allocations
+        allocations.delete()
+
+    @transaction.atomic
+    def unallocateUntracked(self, part=None):
+        """
+        Unallocate all "untracked" stock
+        """
+
+        allocations = BuildItem.objects.filter(
+            build=self,
+            install_into=None
+        )
+
+        if part:
+            allocations = allocations.filter(stock_item__part=part)
+
+        allocations.delete()
+
+    @transaction.atomic
+    def unallocateAll(self):
+        """
+        Deletes all stock allocations for this build.
+        """
+        
+        allocations = BuildItem.objects.filter(build=self)
+
         allocations.delete()
 
     @transaction.atomic
@@ -685,7 +709,7 @@ class Build(MPTTModel):
         output.delete()
 
     @transaction.atomic
-    def autoAllocate(self, output):
+    def autoAllocate(self):
         """
         Run auto-allocation routine to allocate StockItems to this Build.
 
@@ -702,7 +726,7 @@ class Build(MPTTModel):
         See: getAutoAllocations()
         """
 
-        allocations = self.getAutoAllocations(output)
+        allocations = self.getAutoAllocations()
 
         for item in allocations:
             # Create a new allocation
@@ -710,7 +734,7 @@ class Build(MPTTModel):
                 build=self,
                 stock_item=item['stock_item'],
                 quantity=item['quantity'],
-                install_into=output,
+                install_into=None
             )
 
             build_item.save()
@@ -779,7 +803,7 @@ class Build(MPTTModel):
         if output:
             quantity *= output.quantity
         else:
-            quantity *= self.remaining
+            quantity *= self.quantity
 
         return quantity
 
@@ -1020,10 +1044,12 @@ class BuildItem(models.Model):
 
         errors = {}
 
-        if not self.install_into:
-            raise ValidationError(_('Build item must specify a build output'))
-
         try:
+
+            # If the 'part' is trackable, then the 'install_into' field must be set!
+            if self.stock_item.part and self.stock_item.part.trackable and not self.install_into:
+                raise ValidationError(_('Build item must specify a build output, as master part is marked as trackable'))
+
             # Allocated part must be in the BOM for the master part
             if self.stock_item.part not in self.build.part.getRequiredParts(recursive=False):
                 errors['stock_item'] = [_("Selected stock item not found in BOM for part '{p}'").format(p=self.build.part.full_name)]
diff --git a/InvenTree/build/templates/build/allocate.html b/InvenTree/build/templates/build/allocate.html
index 1b66f17d0d..fb4a8200e7 100644
--- a/InvenTree/build/templates/build/allocate.html
+++ b/InvenTree/build/templates/build/allocate.html
@@ -38,6 +38,41 @@
 </div>
 
 <hr>
+
+<div class="panel panel-default" id='allocation-panel-untracked'>
+<div class="panel-heading" role="tab" id="heading-untracked">
+    <div class="panel-title">
+        <div class='row'>
+            <a class='collapsed' aria-expanded='false' role="button" data-toggle="collapse" data-parent="#build-output-accordion" href="#collapse-untracked" aria-controls="collapse-untracked">
+            <div class='col-sm-6'>
+                <span class='fas fa-caret-right'></span>
+                {% trans "Allocated Stock" %}
+            </div>
+        </a>
+        <div class='col-sm-3'>
+            <div>
+                <div id='output-progress-untracked'>
+                    <span class='fas fa-spin fa-spinner'></span>
+                </div>
+            </div>
+        </div>
+        <div class='col-sm-3'>
+            <div class='btn-group float-right' id='output-actions-untracked'>
+                <span class='fas fa-spin fa-spinner'></span>
+            </div>
+        </div>
+    </div>
+</div>
+</div>
+<div id="collapse-untracked" class="panel-collapse collapse" role="tabpanel" aria-labelledby="heading-untracked">
+    <div class="panel-body">
+        <table class='table table-striped table-condensed' id='allocation-table-untracked'></table>
+    </div>
+</div>
+</div>
+
+<hr>
+
 {% if build.incomplete_outputs %}
 <div class="panel-group" id="build-output-accordion" role="tablist" aria-multiselectable="true">
     {% for item in build.incomplete_outputs %}
@@ -66,6 +101,9 @@
         part: {{ build.part.pk }},
     };
 
+    // Load allocation table for un-tracked parts
+    loadBuildOutputAllocationTable(buildInfo, null);
+
     {% for item in build.incomplete_outputs %}
     // Get the build output as a javascript object
     inventreeGet('{% url 'api-stock-detail' item.pk %}', {},
diff --git a/InvenTree/build/templates/build/navbar.html b/InvenTree/build/templates/build/navbar.html
index 5e27010861..383f3c843f 100644
--- a/InvenTree/build/templates/build/navbar.html
+++ b/InvenTree/build/templates/build/navbar.html
@@ -27,7 +27,7 @@
     <li class='list-group-item {% if tab == "allocate" %}active{% endif %}' title='{% trans "In Progress" %}'>
         <a href='{% url "build-allocate" build.id %}'>
             <span class='fas fa-tools'></span>
-            {% trans "In Progress" %}
+            {% trans "Allocate Stock" %}
         </a>
     </li>
     {% endif %}
diff --git a/InvenTree/build/views.py b/InvenTree/build/views.py
index 15ced77130..c467d374ba 100644
--- a/InvenTree/build/views.py
+++ b/InvenTree/build/views.py
@@ -18,7 +18,7 @@ from stock.models import StockLocation, StockItem
 
 from InvenTree.views import AjaxUpdateView, AjaxCreateView, AjaxDeleteView
 from InvenTree.views import InvenTreeRoleMixin
-from InvenTree.helpers import str2bool, extract_serial_numbers, normalize
+from InvenTree.helpers import str2bool, extract_serial_numbers, normalize, isNull
 from InvenTree.status_codes import BuildStatus
 
 
@@ -98,16 +98,6 @@ class BuildAutoAllocate(AjaxUpdateView):
 
         initials = super().get_initial()
 
-        # Pointing to a particular build output?
-        output = self.get_param('output')
-
-        if output:
-            try:
-                output = StockItem.objects.get(pk=output)
-                initials['output'] = output
-            except (ValueError, StockItem.DoesNotExist):
-                pass
-
         return initials
 
     def get_context_data(self, *args, **kwargs):
@@ -121,16 +111,7 @@ class BuildAutoAllocate(AjaxUpdateView):
 
         form = self.get_form()
 
-        output_id = form['output'].value()
-
-        try:
-            output = StockItem.objects.get(pk=output_id)
-        except (ValueError, StockItem.DoesNotExist):
-            output = None
-
-        if output:
-            context['output'] = output
-            context['allocations'] = build.getAutoAllocations(output)
+        context['allocations'] = build.getAutoAllocations()
 
         context['build'] = build
 
@@ -140,18 +121,11 @@ class BuildAutoAllocate(AjaxUpdateView):
 
         form = super().get_form()
 
-        if form['output'].value():
-            # Hide the 'output' field
-            form.fields['output'].widget = HiddenInput()
-
         return form
 
     def validate(self, build, form, **kwargs):
 
-        output = form.cleaned_data.get('output', None)
-
-        if not output:
-            form.add_error(None, _('Build output must be specified'))
+        pass
 
     def save(self, build, form, **kwargs):
         """
@@ -159,9 +133,7 @@ class BuildAutoAllocate(AjaxUpdateView):
         perform auto-allocations
         """
 
-        output = form.cleaned_data.get('output', None)
-
-        build.autoAllocate(output)
+        build.autoAllocate()
 
     def get_data(self):
         return {
@@ -365,10 +337,16 @@ class BuildUnallocate(AjaxUpdateView):
 
         output_id = request.POST.get('output_id', None)
 
-        try:
-            output = StockItem.objects.get(pk=output_id)
-        except (ValueError, StockItem.DoesNotExist):
-            output = None
+        if output_id:
+
+            # If a "null" output is provided, we are trying to unallocate "untracked" stock
+            if isNull(output_id):
+                output = None
+            else:
+                try:
+                    output = StockItem.objects.get(pk=output_id)
+                except (ValueError, StockItem.DoesNotExist):
+                    output = None
 
         part_id = request.POST.get('part_id', None)
 
@@ -383,9 +361,19 @@ class BuildUnallocate(AjaxUpdateView):
             form.add_error('confirm', _('Confirm unallocation of build stock'))
             form.add_error(None, _('Check the confirmation box'))
         else:
-            build.unallocateStock(output=output, part=part)
+
             valid = True
 
+            # Unallocate the entire build
+            if not output_id:
+                build.unallocateAll()
+            # Unallocate a single output
+            elif output:
+                build.unallocateOutput(output, part=part)
+            # Unallocate "untracked" parts
+            else:
+                build.unallocateUntracked(part=part)
+        
         data = {
             'form_valid': valid,
         }
diff --git a/InvenTree/templates/js/build.js b/InvenTree/templates/js/build.js
index 539d1565aa..cdfd6756aa 100644
--- a/InvenTree/templates/js/build.js
+++ b/InvenTree/templates/js/build.js
@@ -37,7 +37,12 @@ function makeBuildOutputActionButtons(output, buildInfo) {
      */
 
     var buildId = buildInfo.pk;
-    var outputId = output.pk;
+
+    if (output) {
+        outputId = output.pk;
+    } else {
+        outputId = 'untracked';
+    }
 
     var panel = `#allocation-panel-${outputId}`;
 
@@ -50,35 +55,40 @@ function makeBuildOutputActionButtons(output, buildInfo) {
 
     var html = `<div class='btn-group float-right' role='group'>`;
 
-    // Add a button to "auto allocate" against the build
-    html += makeIconButton(
-        'fa-magic icon-blue', 'button-output-auto', outputId,
-        '{% trans "Auto-allocate stock items to this output" %}',
-    );
-
-    // Add a button to "complete" the particular build output
-    html += makeIconButton(
-        'fa-check icon-green', 'button-output-complete', outputId,
-        '{% trans "Complete build output" %}',
-        {
-            //disabled: true
-        }
-    );
+    // "Auto" allocation only works for untracked stock items
+    if (!output) {
+        html += makeIconButton(
+            'fa-magic icon-blue', 'button-output-auto', outputId,
+            '{% trans "Auto-allocate stock items to this output" %}',
+            );
+    }
 
     // Add a button to "cancel" the particular build output (unallocate)
     html += makeIconButton(
         'fa-minus-circle icon-red', 'button-output-unallocate', outputId,
         '{% trans "Unallocate stock from build output" %}',
-    );
+        );
 
-    // Add a button to "delete" the particular build output
-    html += makeIconButton(
-        'fa-trash-alt icon-red', 'button-output-delete', outputId,
-        '{% trans "Delete build output" %}',
-    );
 
-    // Add a button to "destroy" the particular build output (mark as damaged, scrap)
-    // TODO
+    if (output) {
+
+        // Add a button to "complete" the particular build output
+        html += makeIconButton(
+            'fa-check icon-green', 'button-output-complete', outputId,
+            '{% trans "Complete build output" %}',
+            {
+                //disabled: true
+            }
+        );
+                    
+        // Add a button to "delete" the particular build output
+        html += makeIconButton(
+            'fa-trash-alt icon-red', 'button-output-delete', outputId,
+            '{% trans "Delete build output" %}',
+            );
+
+        // TODO - Add a button to "destroy" the particular build output (mark as damaged, scrap)
+    }
 
     html += '</div>';
 
@@ -90,7 +100,6 @@ function makeBuildOutputActionButtons(output, buildInfo) {
         launchModalForm(`/build/${buildId}/auto-allocate/`,
             {
                 data: {
-                    output: outputId,
                 },
                 success: reloadTable,
             }
@@ -115,7 +124,7 @@ function makeBuildOutputActionButtons(output, buildInfo) {
             {
                 success: reloadTable,
                 data: {
-                    output: outputId,
+                    output: output ? outputId : 'null',
                 }
             }
         );
@@ -152,13 +161,21 @@ function loadBuildOutputAllocationTable(buildInfo, output, options={}) {
 
     var outputId = null;
     
-    outputId = output.pk;
+    if (output) {
+        outputId = output.pk;
+    } else {
+        outputId = 'untracked';
+    }
 
     var table = options.table;
     
     if (options.table == null) {
         table = `#allocation-table-${outputId}`;
     }
+
+    // If an "output" is specified, then only "trackable" parts are allocated
+    // Otherwise, only "untrackable" parts are allowed
+    var trackable = ! !output;
     
     function reloadTable() {
         // Reload the entire build allocation table
@@ -168,7 +185,13 @@ function loadBuildOutputAllocationTable(buildInfo, output, options={}) {
     function requiredQuantity(row) {
         // Return the requied quantity for a given row
 
-        return row.quantity * output.quantity;
+        if (output) {
+            // "Tracked" parts are calculated against individual build outputs
+            return row.quantity * output.quantity;
+        } else {
+            // "Untracked" parts are specified against the build itself
+            return row.quantity * buildInfo.quantity;
+        }
     }
 
     function sumAllocations(row) {
@@ -300,6 +323,7 @@ function loadBuildOutputAllocationTable(buildInfo, output, options={}) {
         queryParams: {
             part: partId,
             sub_part_detail: true,
+            sub_part_trackable: trackable,
         },
         formatNoMatches: function() { 
             return '{% trans "No BOM items found" %}';
@@ -310,11 +334,19 @@ function loadBuildOutputAllocationTable(buildInfo, output, options={}) {
         onLoadSuccess: function(tableData) {
             // Once the BOM data are loaded, request allocation data for this build output
 
+            var params = {
+                build: buildId,
+            }
+
+            if (output) {
+                params.sub_part_trackable = true;
+                params.output = outputId;
+            } else {
+                params.sub_part_trackable = false;
+            }
+
             inventreeGet('/api/build/item/',
-                {
-                    build: buildId,
-                    output: outputId,
-                },
+                params,
                 {
                     success: function(data) {
                         // Iterate through the returned data, and group by the part they point to
@@ -355,8 +387,16 @@ function loadBuildOutputAllocationTable(buildInfo, output, options={}) {
                             // Calculate the total allocated quantity
                             var allocatedQuantity = sumAllocations(tableRow);
 
+                            var requiredQuantity = 0;
+
+                            if (output) {
+                                requiredQuantity = tableRow.quantity * output.quantity;
+                            } else {
+                                requiredQuantity = tableRow.quantity * buildInfo.quantity;
+                            }
+
                             // Is this line item fully allocated?
-                            if (allocatedQuantity >= (tableRow.quantity * output.quantity)) {
+                            if (allocatedQuantity >= requiredQuantity) {
                                 allocatedLines += 1;
                             }