diff --git a/app/models/payments/base.rb b/app/models/payments/base.rb
index 668c7d63d..d8b94e03d 100644
--- a/app/models/payments/base.rb
+++ b/app/models/payments/base.rb
@@ -26,24 +26,8 @@ module Payments
       transaction.save!
     end
 
-    def complete_transaction
-      raise NotImplementedError
-    end
-
-    def settled_payment?
-      raise NotImplementedError
-    end
-
-    def form_fields
-      raise NotImplementedError
-    end
-
     def form_url
       ENV["payments_#{type}_url"]
     end
-
-    def valid_response?
-      raise NotImplementedError
-    end
   end
 end
diff --git a/test/models/payments/every_pay_test.rb b/test/models/payments/every_pay_test.rb
index a49a5a639..5e09f2980 100644
--- a/test/models/payments/every_pay_test.rb
+++ b/test/models/payments/every_pay_test.rb
@@ -38,8 +38,7 @@ class EveryPayTest < ActiveSupport::TestCase
     @every_pay = Payments::EveryPay.new('every_pay', @invoice, params)
     @other_pay = Payments::EveryPay.new('every_pay', @invoice, {})
 
-    # To avoid problems with time conversion.
-    travel_to Time.at(1522542600)
+    travel_to Time.zone.parse('2018-04-01 00:30:00 +0000')
   end
 
   def teardown
diff --git a/test/models/payments_test.rb b/test/models/payments_test.rb
index 2d51adcf2..2579af20b 100644
--- a/test/models/payments_test.rb
+++ b/test/models/payments_test.rb
@@ -27,20 +27,20 @@ class PaymentTest < ActiveSupport::TestCase
     assert_nil @not_implemented_payment.form_url
   end
 
-  def test_that_errors_are_raised_on_not_implemented_methods
-    assert_raise NotImplementedError do
+  def test_that_errors_are_raised_on_missing_methods
+    assert_raise NoMethodError do
       @not_implemented_payment.valid_response?
     end
 
-    assert_raise NotImplementedError do
+    assert_raise NoMethodError do
       @not_implemented_payment.settled_payment?
     end
 
-    assert_raise NotImplementedError do
+    assert_raise NoMethodError do
       @not_implemented_payment.form_fields
     end
 
-    assert_raise NotImplementedError do
+    assert_raise NoMethodError do
       @not_implemented_payment.complete_transaction
     end
   end