diff --git a/app/main/views/send.py b/app/main/views/send.py
index 8db4d931e..a4bcf08cf 100644
--- a/app/main/views/send.py
+++ b/app/main/views/send.py
@@ -335,6 +335,18 @@ def get_notification_check_endpoint(service_id, template):
     ))
 
 
+def get_letter_address_from_session():
+    """
+    Takes non-blank-string address values out of the placeholders, and returns a multi line string
+    """
+    keys = [f'address line {i}' for i in range(1, 7)] + ['postcode']
+    return '\n'.join([
+        session['placeholders'][key]
+        for key in keys
+        if session['placeholders'].get(key)
+    ])
+
+
 @main.route(
     "/services/<uuid:service_id>/send/<uuid:template_id>/one-off/address",
     methods=['GET', 'POST']
@@ -364,7 +376,9 @@ def send_one_off_letter_address(service_id, template_id):
         sms_sender=None
     )
 
-    form = LetterAddressForm()
+    current_session_address = get_letter_address_from_session()
+
+    form = LetterAddressForm(address=current_session_address)
 
     if form.validate_on_submit():
         session['placeholders'].update(form.as_address_lines_1_to_7_with_postcode)
@@ -467,6 +481,10 @@ def send_test_step(service_id, template_id, step_index):
             template_id=template_id,
         ))
 
+    # if we're in a letter, we should show address block rather than "address line #" or "postcode"
+    if db_template['template_type'] == 'letter' and current_placeholder in first_column_headings['letter']:
+        return redirect(url_for('.send_one_off_letter_address', service_id=service_id, template_id=template_id))
+
     optional_placeholder = (current_placeholder in optional_address_columns)
     form = get_placeholder_form_instance(
         current_placeholder,
diff --git a/tests/app/main/views/test_send.py b/tests/app/main/views/test_send.py
index 9a3352184..84398c3e3 100644
--- a/tests/app/main/views/test_send.py
+++ b/tests/app/main/views/test_send.py
@@ -2015,66 +2015,34 @@ def test_send_test_caches_page_count(
         assert session['send_test_letter_page_count'] == 9
 
 
-def test_send_test_indicates_optional_address_columns(
+def test_send_one_off_back_link_populates_address_textarea(
     client_request,
     mocker,
     mock_get_service_letter_template,
+    mock_template_preview,
     fake_uuid,
 ):
-
-    mocker.patch('app.main.views.send.get_page_count_for_letter', return_value=1)
-
     with client_request.session_transaction() as session:
         session['recipient'] = None
-        session['placeholders'] = {}
+        session['placeholders'] = {'address line 1': 'foo', 'address line 2': 'bar', 'address line 3': ''}
 
+    # imagine someone hit the back button to go from line 3 page to line 2 page
     page = client_request.get(
         'main.send_test_step',
         service_id=SERVICE_ONE_ID,
         template_id=fake_uuid,
-        step_index=3,
-    )
-
-    assert normalize_spaces(page.select('label')[0].text) == (
-        'address line 4 '
-        'Optional'
-    )
-    assert page.select('.govuk-back-link')[0]['href'] == url_for(
-        'main.send_one_off_step',
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
         step_index=2,
+        _follow_redirects=True
     )
 
+    assert page.select_one('h1').text.strip() == 'Send ‘Two week reminder’'
 
-def test_send_test_allows_empty_optional_address_columns(
-    client_request,
-    mocker,
-    mock_get_service_letter_template,
-    fake_uuid,
-):
+    form = page.select_one('form')
+    assert form.select_one('label').text.strip() == 'Address'
 
-    mocker.patch('app.main.views.send.get_page_count_for_letter', return_value=1)
-
-    with client_request.session_transaction() as session:
-        session['recipient'] = None
-        session['placeholders'] = {}
-
-    client_request.post(
-        'main.send_test_step',
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        step_index=3,
-        # no data here
-        _expected_status=302,
-        _expected_redirect=url_for(
-            'main.send_test_step',
-            service_id=SERVICE_ONE_ID,
-            template_id=fake_uuid,
-            step_index=4,
-            _external=True,
-        ),
-    )
+    textarea = form.select_one('textarea')
+    assert textarea.attrs['name'] == 'address'
+    assert textarea.text == 'foo\nbar'
 
 
 def test_send_test_sms_message_puts_submitted_data_in_session(