diff --git a/api/src/services/form_phase_service.py b/api/src/services/form_phase_service.py
index e76bfd1..fdd85f5 100644
--- a/api/src/services/form_phase_service.py
+++ b/api/src/services/form_phase_service.py
@@ -106,10 +106,21 @@ class FormPhaseService:
             form_phase=body,
             budget_form=budget_form,
         )
+        budget_form_id = budget_form_id or budget_form.id
         opens_at = to_org_local_naive(body.opens_at, utc_offset)
         closes_at = to_org_local_naive(body.closes_at, utc_offset)
+        existing = await self.fp_repo.get(
+            budget_form_id=budget_form_id,
+            sheet=body.sheet,
+            direction=body.direction,
+            phase_code=body.phase_code,
+        )
+        if existing:
+            raise ValidationsError(
+                errors={"phase_code": ["Этап с таким названием уже есть на этом листе и направлении"]}
+            )
         return await self.fp_repo.create(
-            budget_form_id=budget_form_id or budget_form.id,
+            budget_form_id=budget_form_id,
             sheet=body.sheet,
             direction=body.direction,
             phase_code=body.phase_code,
diff --git a/api/tests/integration/test_form_phases_api_smoke.py b/api/tests/integration/test_form_phases_api_smoke.py
index bd3901a..c736f50 100644
--- a/api/tests/integration/test_form_phases_api_smoke.py
+++ b/api/tests/integration/test_form_phases_api_smoke.py
@@ -421,3 +421,122 @@ def test_form_phases_create_aware_dates_keep_instant(client, admin_tokens):
         assert _instant(patched["opens_at"]) == _instant(body["opens_at"])
     finally:
         client.delete("/api/v1/stages/form/4/AHR/tz_aware_phase", headers=headers)
+
+
+# AURORA-1879: одноимённые этапы Support/Development и дубли на листе без направления.
+def _phase_body(phase_code, role, direction, opens="2026-01-01T00:00:00", closes="2026-12-31T00:00:00", sheet="AHR"):
+    return {
+        "sheet": sheet,
+        "phase_code": phase_code,
+        "role": role,
+        "column_keys": ["plan.q1"],
+        "opens_at": opens,
+        "closes_at": closes,
+        "direction": direction,
+    }
+
+
+def _create_same_name_phases(client, headers):
+    sup = _phase_body("T_same", "DFIP", "Support")
+    dev = _phase_body("T_same", "EXECUTOR_RF", "Development", "2026-02-01T00:00:00", "2026-11-30T00:00:00")
+    assert client.post("/api/v1/stages/form/1", json=sup, headers=headers).status_code == 200
+    assert client.post("/api/v1/stages/form/1", json=dev, headers=headers).status_code == 200
+
+
+def _list_same(client, headers, query=""):
+    response = client.get(f"/api/v1/stages/form/1?phase_code=T_same{query}", headers=headers)
+    assert response.status_code == 200
+    return response.json()["result"]
+
+
+def test_form_phases_same_name_both_directions_listed(client, admin_tokens):
+    headers = _auth_headers(admin_tokens)
+    _create_same_name_phases(client, headers)
+
+    result = _list_same(client, headers)
+    by_direction = {p["direction"]: p for p in result}
+    assert len(result) == 2
+    assert by_direction["Support"]["role"] == "DFIP"
+    assert by_direction["Development"]["role"] == "EXECUTOR_RF"
+    assert by_direction["Support"]["opens_at"][:10] == "2026-01-01"
+    assert by_direction["Development"]["opens_at"][:10] == "2026-02-01"
+
+    only_dev = _list_same(client, headers, "&sheet=AHR&direction=Development")
+    assert len(only_dev) == 1
+    assert only_dev[0]["direction"] == "Development"
+
+
+def test_form_phases_patch_touches_only_one_direction(client, admin_tokens):
+    headers = _auth_headers(admin_tokens)
+    _create_same_name_phases(client, headers)
+
+    response = client.patch(
+        "/api/v1/stages/form/1/AHR/T_same?direction=Development",
+        json={"role": "DFIP"},
+        headers=headers,
+    )
+    assert response.status_code == 200
+    by_direction = {p["direction"]: p for p in _list_same(client, headers)}
+    assert by_direction["Development"]["role"] == "DFIP"
+    assert by_direction["Support"]["role"] == "DFIP"
+    assert by_direction["Support"]["opens_at"][:10] == "2026-01-01"
+    assert by_direction["Support"]["closes_at"][:10] == "2026-12-31"
+    assert by_direction["Development"]["closes_at"][:10] == "2026-11-30"
+
+
+def test_form_phases_delete_removes_only_named_phase(client, admin_tokens):
+    headers = _auth_headers(admin_tokens)
+    _create_same_name_phases(client, headers)
+    other = _phase_body("T_other", "DFIP", "Support")
+    assert client.post("/api/v1/stages/form/1", json=other, headers=headers).status_code == 200
+
+    response = client.delete("/api/v1/stages/form/1/AHR/T_same?direction=Support", headers=headers)
+    assert response.status_code == 200
+
+    result = client.get("/api/v1/stages/form/1?sheet=AHR", headers=headers).json()["result"]
+    left = {(p["phase_code"], p["direction"]) for p in result if p["phase_code"] in ("T_same", "T_other")}
+    assert left == {("T_other", "Support"), ("T_same", "Development")}
+
+
+def test_form_phases_delete_unknown_phase_code_404(client, admin_tokens):
+    headers = _auth_headers(admin_tokens)
+    # в фикстуре на форме 1, лист AHR, Support один этап "test"
+    before = client.get("/api/v1/stages/form/1?sheet=AHR&direction=Support", headers=headers).json()["result"]
+    response = client.delete("/api/v1/stages/form/1/AHR/no_such_phase?direction=Support", headers=headers)
+    assert response.status_code == 404
+    after = client.get("/api/v1/stages/form/1?sheet=AHR&direction=Support", headers=headers).json()["result"]
+    assert [p["phase_code"] for p in after] == [p["phase_code"] for p in before]
+    assert any(p["phase_code"] == "test" for p in after)
+
+
+def test_form_phases_duplicate_without_direction_rejected(client, admin_tokens):
+    headers = _auth_headers(admin_tokens)
+    body = _phase_body("T_dup", "DFIP", None, sheet="OPER")
+    first = client.post("/api/v1/stages/form/1", json=body, headers=headers)
+    assert first.status_code == 200
+    second = client.post("/api/v1/stages/form/1", json=body, headers=headers)
+    assert 400 <= second.status_code < 500
+    assert "phase_code" in second.text
+
+    result = client.get("/api/v1/stages/form/1?sheet=OPER&phase_code=T_dup", headers=headers).json()["result"]
+    assert len(result) == 1
+
+
+def test_form_phases_patch_audit_has_direction(client, admin_tokens, svod2_sql):
+    headers = _auth_headers(admin_tokens)
+    _create_same_name_phases(client, headers)
+    response = client.patch(
+        "/api/v1/stages/form/1/AHR/T_same?direction=Development",
+        json={"role": "DFIP"},
+        headers=headers,
+    )
+    assert response.status_code == 200
+
+    rows = svod2_sql(
+        "SELECT event, event_data->>'direction', event_data->>'phase_id' FROM v3.audit_log "
+        "WHERE event LIKE 'ACCESS_%' ORDER BY id DESC LIMIT 1"
+    )
+    assert rows, "аудит ACCESS_* не записан"
+    event, direction, phase_id = rows[0]
+    assert direction == "Development"
+    assert phase_id == "1:AHR:Development:T_same"
diff --git a/api/tests/unit/test_form_phase_service.py b/api/tests/unit/test_form_phase_service.py
index a89db12..0664f22 100644
--- a/api/tests/unit/test_form_phase_service.py
+++ b/api/tests/unit/test_form_phase_service.py
@@ -60,3 +60,36 @@ async def test_get_list_no_role_filter_for_admin(service_with_mock_repo, admin_u
         phase_code=None,
         role=None,
     )
+
+
+@pytest.mark.asyncio
+async def test_create_rejects_existing_phase(service_with_mock_repo, admin_user):
+    from src.core.errors import ValidationsError
+    from src.domain.schemas import FormPhaseCreate
+
+    service, mock_repo = service_with_mock_repo
+    mock_repo.get = AsyncMock(return_value=SimpleNamespace(phase_code="T_dup"))
+    mock_repo.create = AsyncMock()
+    body = FormPhaseCreate(
+        sheet="OPER",
+        phase_code="T_dup",
+        role="DFIP",
+        column_keys=["plan.q1"],
+        opens_at="2026-01-01T00:00:00",
+        closes_at="2026-12-31T00:00:00",
+        direction=None,
+    )
+    budget_form = SimpleNamespace(
+        id=1, form_type=SimpleNamespace(sheet_list_with_directions=None, section_list=None)
+    )
+
+    with pytest.raises(ValidationsError) as exc:
+        await service.create(body=body, user=admin_user, budget_form=budget_form)
+
+    assert exc.value.errors == {
+        "phase_code": ["Этап с таким названием уже есть на этом листе и направлении"]
+    }
+    mock_repo.get.assert_awaited_once_with(
+        budget_form_id=1, sheet="OPER", direction=None, phase_code="T_dup"
+    )
+    mock_repo.create.assert_not_awaited()
diff --git a/api/tests/unit/test_form_phase_service_tz.py b/api/tests/unit/test_form_phase_service_tz.py
index 019a58a..5e994db 100644
--- a/api/tests/unit/test_form_phase_service_tz.py
+++ b/api/tests/unit/test_form_phase_service_tz.py
@@ -56,6 +56,7 @@ def _admin():
 def _form_service():
     service = FormPhaseService(db=AsyncMock())
     service.fp_repo = AsyncMock()
+    service.fp_repo.get.return_value = None  # этапа с таким именем ещё нет
     form = SimpleNamespace(
         id=1,
         form_type=SimpleNamespace(section_list=["plan"], sheet_list_with_directions=None),