diff --git a/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py b/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py
index 2b363dc..ae378fc 100644
--- a/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py
+++ b/rattail_corepos/corepos/importing/db/exporters/catapult_inventory.py
@@ -31,6 +31,7 @@ from sqlalchemy import orm
 
 from corepos import enum as corepos_enum
 from corepos.db.office_op import model as corepos
+from corepos.db.util import table_exists
 
 from rattail.gpc import GPC
 from rattail.util import OrderedDict
@@ -139,15 +140,21 @@ class InventoryItemImporter(FromCore, catapult_importing.model.InventoryItemImpo
             'corepos', 'exporting.catapult_inventory.warn_truncated_memo',
             default=True)
 
-        try:
-            self.host_session.query(corepos.FloorSection).count()
-        except ProgrammingError as error:
-            if "doesn't exist" in str(error):
-                self.floor_sections_exist = False
-            else:
-                raise
-        else:
-            self.floor_sections_exist = True
+        self.floor_sections_exist = table_exists(self.host_session,
+                                                 corepos.FloorSection)
+        self.tax_components_exist = table_exists(self.host_session,
+                                                 corepos.TaxRateComponent)
+
+        self.tax_rate_ids_1 = self.config.getlist(
+            'corepos', 'exporting.catapult_inventory.tax_rate_ids_1', default=[])
+        self.tax_rate_ids_1 = [int(id) for id in self.tax_rate_ids_1]
+        self.tax_rate_ids_2 = self.config.getlist(
+            'corepos', 'exporting.catapult_inventory.tax_rate_ids_2', default=[])
+        self.tax_rate_ids_2 = [int(id) for id in self.tax_rate_ids_2]
+
+        # TODO: should add component id levels too?
+        # tax_component_ids_1 = (1,)
+        # tax_component_ids_2 = (2,)
 
     def query(self):
         query = self.host_session.query(corepos.Product)\
@@ -158,7 +165,8 @@ class InventoryItemImporter(FromCore, catapult_importing.model.InventoryItemImpo
                                           .joinedload(corepos.VendorItem.vendor))\
                                  .options(orm.joinedload(corepos.Product.default_vendor))\
                                  .options(orm.joinedload(corepos.Product.scale_item))\
-                                 .options(orm.joinedload(corepos.Product.user_info))
+                                 .options(orm.joinedload(corepos.Product.user_info))\
+                                 .options(orm.joinedload(corepos.Product.tax_rate))
         if self.floor_sections_exist:
             query = query.options(orm.joinedload(corepos.Product.physical_location)\
                                   .joinedload(corepos.ProductPhysicalLocation.floor_section))
@@ -181,6 +189,7 @@ class InventoryItemImporter(FromCore, catapult_importing.model.InventoryItemImpo
             log.debug("ignoring UPC %s for product: %s", product.upc, product)
             return
 
+        # convert item_id either to a PLU, or formatted UPC
         is_plu = False
         if len(str(int(item_id))) < 6:
             is_plu = True
@@ -192,8 +201,10 @@ class InventoryItemImporter(FromCore, catapult_importing.model.InventoryItemImpo
             # drop leading zero(s)
             if item_id[1] == '0': # UPC-A
                 item_id = item_id[2:]
+                assert len(item_id) == 12
             else: # EAN13
                 item_id = item_id[1:]
+                assert len(item_id) == 13
 
         department = product.department
         if not department:
@@ -218,31 +229,31 @@ class InventoryItemImporter(FromCore, catapult_importing.model.InventoryItemImpo
         if product.scale and len(item_id) == 12 and item_id[0] == '2':
             weight_profile = 'LBNT'
 
-        # TODO: need to finish the logic to map/calculate tax rates
+        # calculate tax rates according to configured "mappings"
         tax_1 = 0
         tax_2 = 0
+        if product.tax_rate:
 
-        # # TODO: should let config drive these somehow, obviously
-        # tax_rate_ids_1 = (1,)
-        # tax_rate_ids_2 = (2,)
-        # tax_component_ids_1 = (1,)
-        # tax_component_ids_2 = (2,)
+            # TODO: need to finish the logic to handle tax components
+            if self.tax_components_exist and product.tax_rate.components:
+                # for component in product.tax_rate.components:
+                #     if tax_component_ids_1 and component.id in tax_component_ids_1:
+                #         tax_1 += component.rate
+                #     if tax_component_ids_2 and component.id in tax_component_ids_2:
+                #         tax_2 += component.rate
+                raise NotImplementedError
 
-        # if product.tax_rate:
-
-        #     if product.tax_rate.components:
-        #         for component in product.tax_rate.components:
-        #             if tax_component_ids_1 and component.id in tax_component_ids_1:
-        #                 tax_1 += component.rate
-        #             if tax_component_ids_2 and component.id in tax_component_ids_2:
-        #                 tax_2 += component.rate
-
-        #     else: # no components
-        #         rate = product.tax_rate
-        #         if tax_rate_ids_1 and rate.id in tax_rate_ids_1:
-        #             tax_1 += rate.rate
-        #         if tax_rate_ids_2 and rate.id in tax_rate_ids_2:
-        #             tax_2 += rate.rate
+            else: # no components
+                rate = product.tax_rate
+                if self.tax_rate_ids_1 and rate.id in self.tax_rate_ids_1:
+                    tax_1 += rate.rate
+                if self.tax_rate_ids_2 and rate.id in self.tax_rate_ids_2:
+                    tax_2 += rate.rate
+                if not (self.tax_rate_ids_1 or self.tax_rate_ids_2) and rate.rate:
+                    log.warning("product %s has unknown tax rate %s (%s) which will "
+                                "be considered as tax 1: %s",
+                                product.upc, rate.rate, rate.description, product)
+                    tax_1 += rate.rate
 
         location = None
         if self.floor_sections_exist and product.physical_location and product.physical_location.floor_section: