diff --git a/app/main/forms.py b/app/main/forms.py
index 8023f40bf..442809940 100644
--- a/app/main/forms.py
+++ b/app/main/forms.py
@@ -561,6 +561,7 @@ class ServiceSmsSenderForm(StripWhitespaceForm):
         validators=[
             DataRequired(message="Can’t be empty"),
             Length(max=11, message="Enter 11 characters or fewer"),
+            Length(min=3, message="Enter 3 characters or more"),
             LettersNumbersAndFullStopsOnly(),
         ]
     )
diff --git a/tests/app/main/test_validators.py b/tests/app/main/test_validators.py
index e3e222686..91a7c5fa5 100644
--- a/tests/app/main/test_validators.py
+++ b/tests/app/main/test_validators.py
@@ -206,3 +206,7 @@ def test_sms_sender_form_validation(
     form.sms_sender.data = '###########'
     form.validate()
     assert 'Use letters and numbers only' == form.errors['sms_sender'][0]
+
+    form.sms_sender.data = '0'
+    form.validate()
+    assert 'Enter 3 characters or more' == form.errors['sms_sender'][0]