diff --git a/src/registrar/forms/domain.py b/src/registrar/forms/domain.py
index 3d79790ca..c4e9fdcb7 100644
--- a/src/registrar/forms/domain.py
+++ b/src/registrar/forms/domain.py
@@ -458,7 +458,7 @@ class DomainOrgNameAddressForm(forms.ModelForm):
         validators=[
             RegexValidator(
                 "^[0-9]{5}(?:-[0-9]{4})?$|^$",
-                message="Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789.",
+                message="Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789.",
             )
         ],
     )
diff --git a/src/registrar/forms/domain_request_wizard.py b/src/registrar/forms/domain_request_wizard.py
index 4fb2f9265..3dc9c157c 100644
--- a/src/registrar/forms/domain_request_wizard.py
+++ b/src/registrar/forms/domain_request_wizard.py
@@ -137,10 +137,10 @@ class OrganizationContactForm(RegistrarForm):
         validators=[
             RegexValidator(
                 "^[0-9]{5}(?:-[0-9]{4})?$|^$",
-                message="Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789.",
+                message="Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789.",
             )
         ],
-        error_messages={"required": ("Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789.")},
+        error_messages={"required": ("Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789.")},
     )
     urbanization = forms.CharField(
         required=False,
diff --git a/src/registrar/forms/portfolio.py b/src/registrar/forms/portfolio.py
index 85bc51240..642b6b46e 100644
--- a/src/registrar/forms/portfolio.py
+++ b/src/registrar/forms/portfolio.py
@@ -17,7 +17,7 @@ class PortfolioOrgAddressForm(forms.ModelForm):
         validators=[
             RegexValidator(
                 "^[0-9]{5}(?:-[0-9]{4})?$|^$",
-                message="Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789.",
+                message="Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789.",
             )
         ],
     )
@@ -38,7 +38,7 @@ class PortfolioOrgAddressForm(forms.ModelForm):
             "state_territory": {
                 "required": "Select the state, territory, or military post where your organization is located."
             },
-            "zipcode": {"required": "Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789."},
+            "zipcode": {"required": "Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789."},
         }
         widgets = {
             # We need to set the required attributed for State/territory
diff --git a/src/registrar/templates/domain_org_name_address.html b/src/registrar/templates/domain_org_name_address.html
index f7f6b558b..0785b6da1 100644
--- a/src/registrar/templates/domain_org_name_address.html
+++ b/src/registrar/templates/domain_org_name_address.html
@@ -42,7 +42,7 @@
 
     {% input_with_errors form.state_territory %}
 
-    {% with add_class="usa-input--small" sublabel_text="Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789." %}
+    {% with add_class="usa-input--small" sublabel_text="Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789." %}
       {% input_with_errors form.zipcode %}
     {% endwith %}
 
diff --git a/src/registrar/templates/domain_request_org_contact.html b/src/registrar/templates/domain_request_org_contact.html
index 72c6e4b6d..44b404bbf 100644
--- a/src/registrar/templates/domain_request_org_contact.html
+++ b/src/registrar/templates/domain_request_org_contact.html
@@ -33,7 +33,7 @@
 
     {% input_with_errors forms.0.state_territory %}
 
-    {% with add_class="usa-input--small" sublabel_text="Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789." %}
+    {% with add_class="usa-input--small" sublabel_text="Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789." %}
       {% input_with_errors forms.0.zipcode %}
     {% endwith %}
 
diff --git a/src/registrar/templates/portfolio_organization.html b/src/registrar/templates/portfolio_organization.html
index 1c59ae726..712d1a6ca 100644
--- a/src/registrar/templates/portfolio_organization.html
+++ b/src/registrar/templates/portfolio_organization.html
@@ -45,7 +45,7 @@
                 {% input_with_errors form.address_line2 %}
                 {% input_with_errors form.city %}
                 {% input_with_errors form.state_territory %}
-                {% with add_class="usa-input--small" sublabel_text="Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789." %}
+                {% with add_class="usa-input--small" sublabel_text="Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789." %}
                     {% input_with_errors form.zipcode %}
                 {% endwith %}
                 <button type="submit" class="usa-button">
diff --git a/src/registrar/tests/test_forms.py b/src/registrar/tests/test_forms.py
index 8ca5b4192..12d9af8ac 100644
--- a/src/registrar/tests/test_forms.py
+++ b/src/registrar/tests/test_forms.py
@@ -33,7 +33,7 @@ class TestFormValidation(MockEppLib):
         form = OrganizationContactForm(data={"zipcode": "nah"})
         self.assertEqual(
             form.errors["zipcode"],
-            ["Enter a 5-digit or 9-digit ZIP code, like 12345 or 12345-6789."],
+            ["Enter a 5-digit or 9-digit zip code, like 12345 or 12345-6789."],
         )
 
     def test_org_contact_zip_valid(self):