diff --git a/backend/tests/test_incident_service.py b/backend/tests/test_incident_service.py
new file mode 100644
index 00000000..ff4c3bca
--- /dev/null
+++ b/backend/tests/test_incident_service.py
@@ -0,0 +1,84 @@
+import pytest
+from unittest.mock import MagicMock
+import sys
+import os
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
+
+from backend.services.incident_service import IncidentService, CORRELATION_THRESHOLD, WINDOW_SECONDS
+
+
+class MockDuplicateService:
+    def __init__(self):
+        self.model = None
+        self._loaded = False
+
+    def load(self):
+        self._loaded = True
+
+
+class TestIncidentServicePrune:
+    def test_prune_removes_old_tickets(self):
+        mock_dup = MockDuplicateService()
+        service = IncidentService(mock_dup)
+        now = 1000.0
+        service._recent = [
+            {"ticket_id": "1", "ts": now - 100},
+            {"ticket_id": "2", "ts": now - WINDOW_SECONDS - 10},
+            {"ticket_id": "3", "ts": now -50},
+        ]
+        service._prune(now)
+        assert len(service._recent) == 2
+        assert all(t["ts"] >= now - WINDOW_SECONDS for t in service._recent)
+
+    def test_prune_keeps_recent_tickets(self):
+        mock_dup = MockDuplicateService()
+        service = IncidentService(mock_dup)
+        now = 1000.0
+        service._recent = [
+            {"ticket_id": "1", "ts": now - 100},
+            {"ticket_id": "2", "ts": now - 200},
+        ]
+        service._prune(now)
+        assert len(service._recent) == 2
+
+
+class TestIncidentServiceCritical:
+    def test_is_critical_priority_critical(self):
+        mock_dup = MockDuplicateService()
+        service = IncidentService(mock_dup)
+        assert service._is_critical("critical", None) is True
+        assert service._is_critical("CRITICAL", None) is True
+
+    def test_is_critical_category_email(self):
+        mock_dup = MockDuplicateService()
+        service = IncidentService(mock_dup)
+        assert service._is_critical(None, "email") is True
+        assert service._is_critical(None, "network") is True
+        assert service._is_critical(None, "authentication") is True
+        assert service._is_critical(None, "exchange") is True
+
+    def test_is_critical_not_critical(self):
+        mock_dup = MockDuplicateService()
+        service = IncidentService(mock_dup)
+        assert service._is_critical("high", "general") is False
+        assert service._is_critical(None, None) is False
+
+
+class TestIncidentServiceCorrelate:
+    def test_correlate_returns_defaults_when_no_model(self):
+        mock_dup = MockDuplicateService()
+        service = IncidentService(mock_dup)
+        result = service.correlate("Test ticket text")
+        assert result["incident_id"] is None
+        assert result["is_major_incident"] is False
+        assert result["ticket_count"] == 0
+        assert result["affected_users"] == 0
+        assert result["similarity"] == 0.0
+
+
+class TestIncidentServiceListActive:
+    def test_list_active_returns_empty_initially(self):
+        mock_dup = MockDuplicateService()
+        service = IncidentService(mock_dup)
+        assert service.list_active() == []
diff --git a/backend/tests/test_ner_service.py b/backend/tests/test_ner_service.py
new file mode 100644
index 00000000..d180059f
--- /dev/null
+++ b/backend/tests/test_ner_service.py
@@ -0,0 +1,111 @@
+import pytest
+from unittest.mock import MagicMock, patch
+import sys
+import os
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
+
+import importlib.util
+
+spec = importlib.util.spec_from_file_location(
+    "ner_service",
+    "/home/itsmaestro/gssoc/HELPDESK.AI/backend/services/ner_service.py"
+)
+ner_module = importlib.util.module_from_spec(spec)
+sys.modules['backend.services.ner_service'] = ner_module
+spec.loader.exec_module(ner_module)
+
+
+class TestNERServiceInit:
+    def test_init_sets_defaults(self):
+        service = ner_module.NERService()
+        assert service.model is None
+        assert service.tokenizer is None
+        assert service.id2label is None
+        assert service.label2id is None
+        assert service._loaded is False
+
+
+class TestNERServiceCleanLabel:
+    def test_clean_label_o_tag(self):
+        service = ner_module.NERService()
+        bio, entity = service._clean_label("O")
+        assert bio == "O"
+        assert entity == ""
+
+    def test_clean_label_b_b_entity(self):
+        service = ner_module.NERService()
+        bio, entity = service._clean_label("B-B-APP_NAME")
+        assert bio == "B"
+        assert entity == "APP_NAME"
+
+    def test_clean_label_i_b_entity(self):
+        service = ner_module.NERService()
+        bio, entity = service._clean_label("I-B-APP_NAME")
+        assert bio == "I"
+        assert entity == "APP_NAME"
+
+    def test_clean_label_b_entity(self):
+        service = ner_module.NERService()
+        bio, entity = service._clean_label("B-ENTITY")
+        assert bio == "B"
+        assert entity == "ENTITY"
+
+    def test_clean_label_i_entity(self):
+        service = ner_module.NERService()
+        bio, entity = service._clean_label("I-ENTITY")
+        assert bio == "I"
+        assert entity == "ENTITY"
+
+    def test_clean_label_unknown_returns_o(self):
+        service = ner_module.NERService()
+        bio, entity = service._clean_label("UNKNOWN")
+        assert bio == "O"
+        assert entity == ""
+
+
+class TestNERServiceLoad:
+    def test_load_without_torch(self):
+        original_has_torch = ner_module._HAS_TORCH
+        ner_module._HAS_TORCH = False
+        try:
+            service = ner_module.NERService()
+            service.load()
+            assert service._loaded is False
+        finally:
+            ner_module._HAS_TORCH = original_has_torch
+
+    def test_load_idempotent(self):
+        service = ner_module.NERService()
+        service._loaded = True
+        service.load()
+        assert service._loaded is True
+
+
+class TestNERServiceExtractEntities:
+    def test_extract_entities_empty_text(self):
+        service = ner_module.NERService()
+        service._loaded = True
+        service._load_failed = True
+        result = service.extract_entities("")
+        assert result == []
+
+
+class TestRegexPatterns:
+    def test_regex_patterns_exist(self):
+        assert hasattr(ner_module, 'REGEX_PATTERNS')
+        patterns = ner_module.REGEX_PATTERNS
+        assert "IP_ADDRESS" in patterns
+        assert "HOSTNAME" in patterns
+        assert "NETWORK_ERROR" in patterns
+        assert "LOGIN_ISSUE" in patterns
+        assert "VLAN" in patterns
+        assert "DATABASE" in patterns
+        assert "SYSTEM" in patterns
+        assert "BROWSER" in patterns
+
+
+class TestNERServiceMaxLen:
+    def test_max_len_constant(self):
+        assert hasattr(ner_module, 'MAX_LEN')
+        assert ner_module.MAX_LEN == 128