diff --git a/sponsors/forms.py b/sponsors/forms.py
index 4ced017c9..33b299322 100644
--- a/sponsors/forms.py
+++ b/sponsors/forms.py
@@ -285,7 +285,10 @@ def __init__(self, *args, **kwargs):
         if self.data:
             self.contacts_formset = SponsorContactFormSet(self.data, **formset_kwargs)
         else:
-            self.contacts_formset = SponsorContactFormSet(**formset_kwargs)
+            self.contacts_formset = SponsorContactFormSet(
+                initial=[{"primary": True}],
+                **formset_kwargs
+            )
 
     def clean(self):
         cleaned_data = super().clean()
diff --git a/sponsors/tests/test_forms.py b/sponsors/tests/test_forms.py
index 49b0515cd..c375b9a2b 100644
--- a/sponsors/tests/test_forms.py
+++ b/sponsors/tests/test_forms.py
@@ -534,6 +534,15 @@ def test_invalidate_form_if_no_primary_contact(self):
         msg = "You have to mark at least one contact as the primary one."
         self.assertIn(msg, form.errors["__all__"])
 
+    def test_initial_primary_contact(self):
+        form = SponsorshipApplicationForm()
+        formset = form.contacts_formset
+
+        self.assertTrue(
+            formset.forms[0].initial.get("primary"),
+            "The primary field in the first contact form should be initially set to True."
+        )
+
 
 class SponsorContactFormSetTests(TestCase):
     def setUp(self):