diff --git a/atst/routes/task_orders/new.py b/atst/routes/task_orders/new.py
index f6e53b75..eaf6f2b2 100644
--- a/atst/routes/task_orders/new.py
+++ b/atst/routes/task_orders/new.py
@@ -70,7 +70,12 @@ def update_task_order(form, portfolio_id=None, task_order_id=None, flash_invalid
 
 
 def update_and_render_next(
-    form_data, next_page, current_template, portfolio_id=None, task_order_id=None
+    form_data,
+    next_page,
+    current_template,
+    portfolio_id=None,
+    task_order_id=None,
+    previous=False,
 ):
     form = None
     if task_order_id:
@@ -80,8 +85,9 @@ def update_and_render_next(
         form = TaskOrderForm(form_data)
 
     task_order = update_task_order(form, portfolio_id, task_order_id)
-    if task_order:
-        return redirect(url_for(next_page, task_order_id=task_order.id))
+    if task_order or previous:
+        to_id = task_order.id if task_order else task_order_id
+        return redirect(url_for(next_page, task_order_id=to_id))
     else:
         return (
             render_task_orders_edit(
@@ -210,12 +216,21 @@ def form_step_two_add_number(task_order_id):
 @task_orders_bp.route("/task_orders/<task_order_id>/form/step_2", methods=["POST"])
 @user_can(Permissions.CREATE_TASK_ORDER, message="update task order form")
 def submit_form_step_two_add_number(task_order_id):
+    previous = http_request.args.get("previous", "False").lower() == "true"
     form_data = {**http_request.form}
-    next_page = "task_orders.form_step_three_add_clins"
+    next_page = (
+        "task_orders.form_step_three_add_clins"
+        if not previous
+        else "task_orders.form_step_one_add_pdf"
+    )
     current_template = "task_orders/step_2.html"
 
     return update_and_render_next(
-        form_data, next_page, current_template, task_order_id=task_order_id
+        form_data,
+        next_page,
+        current_template,
+        task_order_id=task_order_id,
+        previous=previous,
     )
 
 
@@ -230,12 +245,21 @@ def form_step_three_add_clins(task_order_id):
 @task_orders_bp.route("/task_orders/<task_order_id>/form/step_3", methods=["POST"])
 @user_can(Permissions.CREATE_TASK_ORDER, message="update task order form")
 def submit_form_step_three_add_clins(task_order_id):
+    previous = http_request.args.get("previous", "False").lower() == "true"
     form_data = {**http_request.form}
-    next_page = "task_orders.form_step_four_review"
+    next_page = (
+        "task_orders.form_step_four_review"
+        if not previous
+        else "task_orders.form_step_two_add_number"
+    )
     current_template = "task_orders/step_3.html"
 
     return update_and_render_next(
-        form_data, next_page, current_template, task_order_id=task_order_id
+        form_data,
+        next_page,
+        current_template,
+        task_order_id=task_order_id,
+        previous=previous,
     )
 
 
diff --git a/templates/task_orders/builder_base.html b/templates/task_orders/builder_base.html
index f5b88c3a..5b819b27 100644
--- a/templates/task_orders/builder_base.html
+++ b/templates/task_orders/builder_base.html
@@ -39,9 +39,20 @@
           {% endblock %}
 
           {% if step != "1" %}
-            <a class="usa-button usa-button-secondary" href="{{ previous_button_link }}">
-              Previous
-            </a>
+            {% if step == "2" or step == "3" -%}
+              <button
+                type="submit"
+                class="usa-button usa-button-secondary"
+                formaction="{{ previous_button_link }}">
+                Previous
+              </button>
+            {% else -%}
+              <a
+                class="usa-button usa-button-secondary"
+                href="{{ previous_button_link }}">
+                Previous
+              </a>
+            {%- endif %}
           {% endif %}
 
           <a
diff --git a/templates/task_orders/step_2.html b/templates/task_orders/step_2.html
index 1a5b0c42..e40f4bfc 100644
--- a/templates/task_orders/step_2.html
+++ b/templates/task_orders/step_2.html
@@ -5,7 +5,7 @@
 
 {% set action = url_for("task_orders.submit_form_step_two_add_number", task_order_id=task_order_id) %}
 {% set next_button_text = "Next: Add Base CLIN" %}
-{% set previous_button_link = url_for("task_orders.form_step_one_add_pdf", task_order_id=task_order_id) %}
+{% set previous_button_link = url_for("task_orders.submit_form_step_two_add_number", task_order_id=task_order_id, previous=True) %}
 {% set step = "2" %}
 {% set sticky_cta_text = 'task_orders.form.sticky_header_text' | translate %}
 
diff --git a/templates/task_orders/step_3.html b/templates/task_orders/step_3.html
index b1788b51..7782c7bd 100644
--- a/templates/task_orders/step_3.html
+++ b/templates/task_orders/step_3.html
@@ -6,7 +6,7 @@
 
 {% set action = url_for("task_orders.submit_form_step_three_add_clins", task_order_id=task_order_id) %}
 {% set next_button_text = "task_orders.form.step_3.next_button" | translate %}
-{% set previous_button_link = url_for("task_orders.form_step_two_add_number", task_order_id=task_order_id) %}
+{% set previous_button_link = url_for("task_orders.submit_form_step_three_add_clins", task_order_id=task_order_id, previous=True) %}
 {% set step = "3" %}
 {% set sticky_cta_text = 'task_orders.form.sticky_header_text' | translate %}
 
diff --git a/tests/routes/task_orders/test_new.py b/tests/routes/task_orders/test_new.py
index 0aef88ed..4855ad83 100644
--- a/tests/routes/task_orders/test_new.py
+++ b/tests/routes/task_orders/test_new.py
@@ -458,3 +458,61 @@ def test_task_order_form_shows_errors(client, user_session, task_order):
     body = response.data.decode()
     assert "There were some errors" in body
     assert "Not a valid decimal" in body
+
+
+def test_update_and_render_next_handles_previous_valid_data(
+    client, user_session, task_order
+):
+    user_session(task_order.portfolio.owner)
+    form_data = {"number": "0000000000000"}
+    original_number = task_order.number
+    response = client.post(
+        url_for(
+            "task_orders.submit_form_step_two_add_number",
+            task_order_id=task_order.id,
+            previous=True,
+        ),
+        data=form_data,
+    )
+    assert response.status_code == 302
+    assert task_order.number == "0000000000000"
+    assert task_order.number != original_number
+
+
+def test_update_and_render_next_handles_previous_invalid_data(
+    client, user_session, task_order
+):
+    clin_list = [
+        {
+            "jedi_clin_type": "JEDI_CLIN_1",
+            "number": "12312",
+            "start_date": "01/01/2020",
+            "end_date": "01/01/2021",
+            "obligated_amount": "5000",
+            "total_amount": "10000",
+        },
+    ]
+    TaskOrders.create_clins(task_order.id, clin_list)
+    assert len(task_order.clins) == 2
+
+    user_session(task_order.portfolio.owner)
+    form_data = {
+        "clins-0-jedi_clin_type": "JEDI_CLIN_1",
+        "clins-0-number": "12312",
+        "clins-0-start_date": "01/01/2020",
+        "clins-0-end_date": "01/01/2021",
+        "clins-0-obligated_amount": "5000",
+        "clins-0-total_amount": "10000",
+        "clins-1-jedi_clin_type": "JEDI_CLIN_1",
+        "clins-1-number": "1212",
+    }
+    response = client.post(
+        url_for(
+            "task_orders.submit_form_step_three_add_clins",
+            task_order_id=task_order.id,
+            previous=True,
+        ),
+        data=form_data,
+    )
+
+    assert len(task_order.clins) == 2