diff --git a/app/crud.py b/app/crud.py
index 09d182d..0410986 100644
--- a/app/crud.py
+++ b/app/crud.py
@@ -368,6 +368,7 @@ def create_ballot(db: Session, ballot: schemas.BallotCreate) -> schemas.BallotGe
     db_election = _check_public_election(db, ballot.election_ref)
     election = schemas.ElectionGet.model_validate(db_election)
 
+    _check_election_is_started(db_election)
     _check_election_is_not_ended(db_election)
 
     _check_items_in_election(
@@ -407,6 +408,14 @@ def _check_public_election(db: Session, election_ref: str):
         )
     return db_election
 
+def _check_election_is_started(election: models.Election):
+    """
+    Check that the election is started.
+    If it is not, raise an error.
+    """
+    if election.date_start is not None and election.date_start > datetime.now():
+        raise errors.ForbiddenError("The election has not started yet. You can not create votes")
+
 def _check_election_is_not_ended(election: models.Election):
     """
     Check that the election is not ended.
@@ -454,6 +463,7 @@ def update_ballot(
     if db_election is None:
         raise errors.NotFoundError("elections")
 
+    _check_election_is_started(db_election)
     _check_election_is_not_ended(db_election)
 
     if len(ballot.votes) != len(vote_ids):
diff --git a/app/schemas.py b/app/schemas.py
index 1adc86c..6db2498 100644
--- a/app/schemas.py
+++ b/app/schemas.py
@@ -115,7 +115,7 @@ class ElectionBase(BaseModel):
     name: Name
     description: Description = ""
     ref: Ref = ""
-    date_start: datetime | int | str = Field(default_factory=_utc_now)
+    date_start: datetime | int | str | None = Field(default_factory=_utc_now)
     date_end: datetime | int | str | None = Field(default_factory=_in_a_long_time)
     hide_results: bool = True
     restricted: bool = False
diff --git a/app/tests/test_api.py b/app/tests/test_api.py
index 69c4835..9330201 100644
--- a/app/tests/test_api.py
+++ b/app/tests/test_api.py
@@ -59,6 +59,7 @@ class RandomElection(t.TypedDict):
     hide_results: bool
     num_voters: int
     date_end: t.Optional[str]
+    date_start: t.Optional[str]
     auth_for_result: bool
 
 
@@ -72,6 +73,7 @@ def _random_election(num_candidates: int, num_grades: int) -> RandomElection:
     candidates = [{"name": _random_string(10)} for i in range(num_candidates)]
     name = _random_string(10)
     return {
+        "date_start":None,
         "candidates": candidates, 
         "grades": grades, 
         "name": name,
@@ -396,6 +398,56 @@ def test_cannot_update_vote_on_ended_election():
 
     assert response.status_code == 403, response.json()
 
+## TODO: cannot change start_date if a people vote; 
+## 
+def test_cannot_create_vote_on_unstarted_election():
+    """
+    On an unstarted election, we are not allowed to create new votes
+    """
+    # Create a random election
+    body = _random_election(10, 5)
+    body["date_start"] = (datetime.now() + timedelta(days=1)).isoformat()
+    body["date_end"] = (datetime.now() + timedelta(days=2)).isoformat()
+    response = client.post("/elections", json=body)
+    data = response.json()
+    assert response.status_code == 200, data
+    election_ref = data["ref"]
+
+    # We create votes using the ID
+    votes = _generate_votes_from_response("id", data)
+    response = client.post(
+        f"/ballots",
+        json={"votes": votes, "election_ref": election_ref},
+    )
+    data = response.json()
+    assert response.status_code == 403, data
+
+def test_cannot_update_vote_on_unstarted_election():
+    """
+    On an unstarted election, we are not allowed to create new votes
+    """
+    # Create a random election
+    body = _random_election(10, 5)
+    body["restricted"] = True
+    body["num_voters"] = 1
+    body["date_start"] = (datetime.now() + timedelta(days=1)).isoformat()
+    body["date_end"] = (datetime.now() + timedelta(days=2)).isoformat()
+    response = client.post("/elections", json=body)
+    data = response.json()
+    assert response.status_code == 200, data
+    election_ref = data["ref"]
+    tokens = data["invites"]
+    assert len(tokens) == 1
+
+    # We create votes using the ID
+    votes = _generate_votes_from_response("id", data)
+    response = client.put(
+        f"/ballots",
+        json={"votes": votes, "election_ref": election_ref},
+        headers={"Authorization": f"Bearer {tokens[0]}"},
+    )
+    data = response.json()
+    assert response.status_code == 403, data
 
 def test_cannot_create_vote_on_restricted_election():
     """