diff --git a/registrasion/controllers/invoice.py b/registrasion/controllers/invoice.py
index 03be199a..1b70640e 100644
--- a/registrasion/controllers/invoice.py
+++ b/registrasion/controllers/invoice.py
@@ -245,6 +245,12 @@ class InvoiceController(ForId, object):
         if residual != 0:
             CreditNoteController.generate_from_invoice(self.invoice, residual)
 
+        self.email_on_invoice_change(
+            self.invoice,
+            old_status,
+            self.invoice.status,
+        )
+
     def _mark_paid(self):
         ''' Marks the invoice as paid, and updates the attached cart if
         necessary. '''
@@ -347,4 +353,15 @@ class InvoiceController(ForId, object):
 
         '''
 
+        # The statuses that we don't care about.
+        silent_status = [
+            commerce.Invoice.STATUS_VOID,
+            commerce.Invoice.STATUS_UNPAID,
+        ]
+
+        if old_status == new_status:
+            return
+        if False and new_status in silent_status:
+            pass
+
         cls.email(invoice, "invoice_updated")
diff --git a/registrasion/tests/test_invoice.py b/registrasion/tests/test_invoice.py
index 32ec6c2e..98d479b6 100644
--- a/registrasion/tests/test_invoice.py
+++ b/registrasion/tests/test_invoice.py
@@ -536,8 +536,37 @@ class InvoiceTestCase(RegistrationCartTestCase):
 
     def test_sends_email_on_invoice_creation(self):
         invoice = self._invoice_containing_prod_1(1)
-        assert(1, len(self.emails))
+        self.assertEquals(1, len(self.emails))
         email = self.emails[0]
         self.assertEquals(self.USER_1.email, email["to"])
         self.assertEquals("invoice_created", email["kind"])
         self.assertEquals(invoice.invoice, email["context"]["invoice"])
+
+    def test_sends_first_change_email_on_invoice_fully_paid(self):
+        invoice = self._invoice_containing_prod_1(1)
+
+        self.assertEquals(1, len(self.emails))
+        invoice.pay("Partial", invoice.invoice.value - 1)
+        # Should have an "invoice_created" email and nothing else.
+        self.assertEquals(1, len(self.emails))
+        invoice.pay("Remainder", 1)
+        self.assertEquals(2, len(self.emails))
+
+        email = self.emails[1]
+        self.assertEquals(self.USER_1.email, email["to"])
+        self.assertEquals("invoice_updated", email["kind"])
+        self.assertEquals(invoice.invoice, email["context"]["invoice"])
+
+    def test_sends_email_when_invoice_refunded(self):
+        invoice = self._invoice_containing_prod_1(1)
+
+        self.assertEquals(1, len(self.emails))
+        invoice.pay("Payment", invoice.invoice.value)
+        self.assertEquals(2, len(self.emails))
+        invoice.refund()
+        self.assertEquals(3, len(self.emails))
+
+        email = self.emails[2]
+        self.assertEquals(self.USER_1.email, email["to"])
+        self.assertEquals("invoice_updated", email["kind"])
+        self.assertEquals(invoice.invoice, email["context"]["invoice"])