diff --git a/app/main/views/dashboard.py b/app/main/views/dashboard.py
index 06b78355b..61a5c6daa 100644
--- a/app/main/views/dashboard.py
+++ b/app/main/views/dashboard.py
@@ -332,13 +332,14 @@ def get_annual_usage_breakdown(usage, free_sms_fragment_limit):
     sms_rate = 0 if len(sms) == 0 else sms[0].get("rate", 0)
     sms_chargeable_units = sum(row['chargeable_units'] for row in sms)
     sms_free_allowance = free_sms_fragment_limit
+    sms_cost = sum(row['cost'] for row in sms)
 
     emails = get_usage_breakdown_by_type(usage, 'email')
     emails_sent = sum(row['notifications_sent'] for row in emails)
 
     letters = get_usage_breakdown_by_type(usage, 'letter')
     letters_sent = sum(row['notifications_sent'] for row in letters)
-    letters_cost = sum(row['letter_total'] for row in letters)
+    letters_cost = sum(row['cost'] for row in letters)
 
     return {
         'emails_sent': emails_sent,
@@ -346,6 +347,7 @@ def get_annual_usage_breakdown(usage, free_sms_fragment_limit):
         'sms_sent': sms_chargeable_units,
         'sms_allowance_remaining': max(0, (sms_free_allowance - sms_chargeable_units)),
         'sms_chargeable': max(0, sms_chargeable_units - sms_free_allowance),
+        'sms_cost': sms_cost,
         'sms_rate': sms_rate,
         'letter_sent': letters_sent,
         'letter_cost': letters_cost
diff --git a/app/templates/views/dashboard/_usage.html b/app/templates/views/dashboard/_usage.html
index 6cad43324..4046e6c91 100644
--- a/app/templates/views/dashboard/_usage.html
+++ b/app/templates/views/dashboard/_usage.html
@@ -8,9 +8,9 @@
   </div>
   <div class='govuk-grid-column-one-third'>
     <div class="keyline-block">
-      {% if sms_chargeable %}
+      {% if sms_cost %}
         {{ big_number(
-          sms_chargeable * sms_rate,
+          sms_cost,
           'spent on text messages',
           currency="£",
           smaller=True
diff --git a/app/templates/views/usage.html b/app/templates/views/usage.html
index 4479c97fa..9f0557a50 100644
--- a/app/templates/views/usage.html
+++ b/app/templates/views/usage.html
@@ -59,7 +59,7 @@
         <div class='govuk-grid-column-one-third'>
           <div class="keyline-block">
             {{ big_number(
-              (sms_chargeable * sms_rate),
+              sms_cost,
               'spent',
               currency="£",
               smaller=True
diff --git a/tests/app/main/views/test_dashboard.py b/tests/app/main/views/test_dashboard.py
index 9dc529a96..4e2341f22 100644
--- a/tests/app/main/views/test_dashboard.py
+++ b/tests/app/main/views/test_dashboard.py
@@ -1020,7 +1020,7 @@ def test_usage_page(
     assert '251,800 sent' in sms_column
     assert '250,000 free allowance' in sms_column
     assert '0 free allowance remaining' in sms_column
-    assert '£36.14 spent' in sms_column
+    assert '£29.85 spent' in sms_column
     assert '1,800 at 1.65 pence' in sms_column
 
     letter_column = normalize_spaces(annual_usage[2].text + annual_usage[5].text)
@@ -1855,7 +1855,7 @@ def test_service_dashboard_shows_usage(
     ) == (
         'Unlimited '
         'free email allowance '
-        '£36.14 '
+        '£29.85 '
         'spent on text messages '
         '£30.00 '
         'spent on letters'
diff --git a/tests/conftest.py b/tests/conftest.py
index 01a5a4db6..68f7b7231 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -2321,28 +2321,28 @@ def mock_get_usage(mocker, service_one, fake_uuid):
                 "chargeable_units": 1000,
                 "notifications_sent": 1000,
                 "rate": 0.00,
-                "letter_total": 0
+                "cost": 0
             },
             {
                 "notification_type": "sms",
                 "chargeable_units": 251500,
                 "notifications_sent": 105000,
                 "rate": 0.0165,
-                "letter_total": 0
+                "cost": 24.75  # 250K free allowance
             },
             {
                 "notification_type": "sms",
                 "chargeable_units": 300,
                 "notifications_sent": 300,
                 "rate": 0.0165,
-                "letter_total": 0
+                "cost": 5.1
             },
             {
                 "notification_type": "letter",
                 "chargeable_units": 300,
                 "notifications_sent": 100,
                 "rate": 0.1,
-                "letter_total": 30
+                "cost": 30
             },
         ]
 
@@ -2467,14 +2467,14 @@ def mock_get_future_usage(mocker, service_one, fake_uuid):
                 'chargeable_units': 0,
                 'notifications_sent': 0,
                 'rate': 0.0158,
-                'letter_total': 0
+                'cost': 0
             },
             {
                 'notification_type': 'email',
                 'chargeable_units': 0,
                 'notifications_sent': 0,
                 'rate': 0.0,
-                'letter_total': 0
+                'cost': 0
             }
         ]