diff --git a/edc_next_appointment/model_mixins.py b/edc_next_appointment/model_mixins.py
index d97d0e8..6854205 100644
--- a/edc_next_appointment/model_mixins.py
+++ b/edc_next_appointment/model_mixins.py
@@ -48,6 +48,15 @@ class NextAppointmentCrfModelMixin(models.Model):
         ),
     )
 
+    allow_create_interim = models.BooleanField(
+        verbose_name=_("Override date check?"),
+        default=False,
+        help_text=(
+            "Override date check to allow the EDC to create an interim appointment if the "
+            "date is within window period of the current appointment."
+        ),
+    )
+
     class Meta:
         abstract = True
         verbose_name = "Next Appointment"
diff --git a/edc_next_appointment/modeladmin_mixins.py b/edc_next_appointment/modeladmin_mixins.py
index e152982..31d42aa 100644
--- a/edc_next_appointment/modeladmin_mixins.py
+++ b/edc_next_appointment/modeladmin_mixins.py
@@ -12,7 +12,15 @@ class NextAppointmentModelAdminMixin:
         (None, {"fields": ("subject_visit", "report_datetime")}),
         (
             "Integrated Clinic",
-            {"fields": ("health_facility", "appt_date", "info_source", "visitschedule")},
+            {
+                "fields": (
+                    "info_source",
+                    "health_facility",
+                    "appt_date",
+                    "allow_create_interim",
+                    "visitschedule",
+                )
+            },
         ),
         crf_status_fieldset_tuple,
         audit_fieldset_tuple,
diff --git a/edc_next_appointment/modelform_mixins.py b/edc_next_appointment/modelform_mixins.py
index 88db0cb..bd5f437 100644
--- a/edc_next_appointment/modelform_mixins.py
+++ b/edc_next_appointment/modelform_mixins.py
@@ -14,22 +14,29 @@
 
 
 class NextAppointmentModelFormMixin:
+    appt_date_fld = "appt_date"
+    visit_code_fld = "visitschedule"
+
     def clean(self):
         cleaned_data = super().clean()
         self.validate_suggested_date_with_future_appointments()
         self.validate_suggested_visit_code()
         return cleaned_data
 
+    @property
+    def allow_create_interim(self) -> str:
+        return self.cleaned_data.get("allow_create_interim", False)
+
     @property
     def suggested_date(self) -> date | None:
-        return self.cleaned_data.get("appt_date")
+        return self.cleaned_data.get(self.appt_date_fld)
 
     @property
     def suggested_visit_code(self) -> str | None:
         return getattr(
-            self.cleaned_data.get("visitschedule"),
+            self.cleaned_data.get(self.visit_code_fld),
             "visit_code",
-            self.cleaned_data.get("visitschedule"),
+            self.cleaned_data.get(self.visit_code_fld),
         )
 
     def validate_suggested_date_with_future_appointments(self):
@@ -48,7 +55,7 @@ def validate_suggested_date_with_future_appointments(self):
                 )
                 raise forms.ValidationError(
                     {
-                        "appt_date": _(
+                        self.appt_date_fld: _(
                             "Invalid. Next visit report already submitted. Expected "
                             "`%(dt)s`. See `%(visit_code)s`."
                         )
@@ -69,7 +76,7 @@ def validate_suggested_date_with_future_appointments(self):
             date_format = convert_php_dateformat(settings.SHORT_DATE_FORMAT)
             raise forms.ValidationError(
                 {
-                    "appt_date": _(
+                    self.appt_date_fld: _(
                         "Invalid. Expected a date before appointment "
                         "`%(visit_code)s` on "
                         "%(dt_str)s."
@@ -95,21 +102,10 @@ def validate_suggested_visit_code(self):
                     raise_if_in_gap=False,
                 )
             except ScheduledVisitWindowError as e:
-                raise forms.ValidationError({"appt_date": str(e)})
+                raise forms.ValidationError({self.appt_date_fld: str(e)})
             if not appointment:
                 raise forms.ValidationError(
-                    {"appt_date": _("Invalid. Must be within the followup period.")}
-                )
-            elif appointment == subject_visit.appointment:
-                raise forms.ValidationError(
-                    {
-                        "appt_date": (
-                            _(
-                                "Invalid. Cannot be within window period "
-                                "of current appointment."
-                            )
-                        )
-                    }
+                    {self.appt_date_fld: _("Invalid. Must be within the followup period.")}
                 )
 
             if (
@@ -119,7 +115,7 @@ def validate_suggested_visit_code(self):
                 date_format = convert_php_dateformat(settings.SHORT_DATE_FORMAT)
                 raise forms.ValidationError(
                     {
-                        "visitschedule": _(
+                        self.visit_code_fld: _(
                             "Expected %(visit_code)s using %(dt_str)s from above."
                         )
                         % {
@@ -128,6 +124,29 @@ def validate_suggested_visit_code(self):
                         }
                     }
                 )
+            if appointment == subject_visit.appointment:
+                if self.allow_create_interim:
+                    pass
+                else:
+                    raise forms.ValidationError(
+                        {
+                            self.appt_date_fld: (
+                                _(
+                                    "Invalid. Cannot be within window period "
+                                    "of the current appointment."
+                                )
+                            )
+                        }
+                    )
+            elif self.allow_create_interim:
+                raise forms.ValidationError(
+                    {
+                        "allow_create_interim": _(
+                            "Cannot override if date is not within window period "
+                            "of the current appointment."
+                        )
+                    }
+                )
 
     @staticmethod
     def as_datetime(dt: date) -> datetime:
diff --git a/edc_next_appointment/tests/tests/test_next_appointment.py b/edc_next_appointment/tests/tests/test_next_appointment.py
index e504038..8c84450 100644
--- a/edc_next_appointment/tests/tests/test_next_appointment.py
+++ b/edc_next_appointment/tests/tests/test_next_appointment.py
@@ -5,7 +5,7 @@
 from dateutil.relativedelta import relativedelta
 from django.contrib.auth.models import User
 from django.core.exceptions import ObjectDoesNotExist
-from django.test import TestCase, override_settings, tag
+from django.test import TestCase, override_settings
 from edc_appointment.constants import SKIPPED_APPT
 from edc_appointment.models import Appointment
 from edc_constants.constants import NOT_APPLICABLE, PATIENT
@@ -74,7 +74,6 @@ def test_ok(self):
         subject_visit_model_cls = get_related_visit_model_cls()
         subject_visit_model_cls.objects.create(appointment=appointment, reason=SCHEDULED)
 
-    @tag("1")
     @override_settings(
         EDC_APPOINTMENT_ALLOW_SKIPPED_APPT_USING={
             "next_appointment_app.nextappointment": ("appt_date", "visitschedule")