diff --git a/tailbone_corepos/views/people.py b/tailbone_corepos/views/people.py
index 9cd6705..f996aef 100644
--- a/tailbone_corepos/views/people.py
+++ b/tailbone_corepos/views/people.py
@@ -57,13 +57,16 @@ class PersonViewSupplement(ViewSupplement):
         model = self.model
         return [model.CorePerson]
 
-    def get_customer_xref_buttons(self, person):
-        buttons = []
-        for customer in person.customers:
-            url = core_office_customer_account_url(
-                self.rattail_config, customer.number)
-            buttons.append({'url': url, 'text': "View in CORE Office"})
-        return buttons
+    def get_context_for_customer(self, customer, context):
+
+        if customer.corepos_card_number:
+            url = core_office_customer_account_url(self.rattail_config,
+                                                   customer.corepos_card_number)
+            if url:
+                context['external_links'].append({'label': "View in CORE Office",
+                                                  'url': url})
+
+        return context
 
     def get_member_xref_buttons(self, person):
         buttons = OrderedDict()