diff --git a/neoexchange/astrometrics/ephem_subs.py b/neoexchange/astrometrics/ephem_subs.py
index 66ebef9f5..ed0ad52d2 100644
--- a/neoexchange/astrometrics/ephem_subs.py
+++ b/neoexchange/astrometrics/ephem_subs.py
@@ -751,10 +751,16 @@ def determine_horizons_id(lines, obj_name, now=None):
 
     now = now or datetime.utcnow()
     timespan = timedelta.max
+    provisional_comet = False
+    if obj_name.lstrip().startswith('C/') or obj_name.lstrip().startswith('P/'):
+        # Provisional comet, need to match on different (combined) columns
+        provisional_comet = True
     horizons_id = None
     for line in lines:
         chunks = line.split()
-        if len(chunks) >= 5 and chunks[0].isdigit() is True and chunks[1].isdigit() is True and chunks[3] == obj_name:
+        if (len(chunks) >= 5 and chunks[0].isdigit() is True and chunks[1].isdigit() is True) and \
+            (chunks[3] == obj_name.strip() or \
+             (provisional_comet is True and chunks[4] + ' ' + chunks[5] == obj_name.strip())):
             try:
                 epoch_yr = datetime.strptime(chunks[1], "%Y")
                 if abs(now-epoch_yr) <= timespan:
diff --git a/neoexchange/astrometrics/tests/test_ephem_subs.py b/neoexchange/astrometrics/tests/test_ephem_subs.py
index 569237aee..144c1b471 100644
--- a/neoexchange/astrometrics/tests/test_ephem_subs.py
+++ b/neoexchange/astrometrics/tests/test_ephem_subs.py
@@ -3657,6 +3657,54 @@ def test_73P(self):
 
         self.assertEqual(expected_id, horizons_id)
 
+    def test_C_2025K1(self):
+        expected_id = 90004909
+        lines = ['Ambiguous target name; provide unique id:',
+                 '    Record #  Epoch-yr  >MATCH DESIG<  Primary Desig  Name  ',
+                 '    --------  --------  -------------  -------------  -------------------------',
+                 '    90004909    2025    C/2025 K1      C/2025 K1       ATLAS',
+                 '    90004910    2025    C/2025 K1-B    C/2025 K1-B     ATLAS',
+                 '    90004911    2025    C/2025 K1-C    C/2025 K1-C     ATLAS',
+                 '']
+        now = datetime(2025, 5, 11, 17, 20, 42)
+        obj_name = 'C/2025 K1'
+
+        horizons_id = determine_horizons_id(lines, obj_name, now)
+
+        self.assertEqual(expected_id, horizons_id)
+
+    def test_C_2025K1c(self):
+        expected_id = 90004911
+        lines = ['Ambiguous target name; provide unique id:',
+                 '    Record #  Epoch-yr  >MATCH DESIG<  Primary Desig  Name  ',
+                 '    --------  --------  -------------  -------------  -------------------------',
+                 '    90004909    2025    C/2025 K1      C/2025 K1       ATLAS',
+                 '    90004910    2025    C/2025 K1-B    C/2025 K1-B     ATLAS',
+                 '    90004911    2025    C/2025 K1-C    C/2025 K1-C     ATLAS',
+                 '']
+        now = datetime(2025, 5, 11, 17, 20, 42)
+        obj_name = 'C/2025 K1-C'
+
+        horizons_id = determine_horizons_id(lines, obj_name, now)
+
+        self.assertEqual(expected_id, horizons_id)
+
+    def test_P_2025K1(self):
+        expected_id = 90004909
+        lines = ['Ambiguous target name; provide unique id:',
+                 '    Record #  Epoch-yr  >MATCH DESIG<  Primary Desig  Name  ',
+                 '    --------  --------  -------------  -------------  -------------------------',
+                 '    90004909    2025    P/2025 K1      P/2025 K1       ATLAS',
+                 '    90004910    2025    P/2025 K1-B    P/2025 K1-B     ATLAS',
+                 '    90004911    2025    P/2025 K1-C    P/2025 K1-C     ATLAS',
+                 '']
+        now = datetime(2025, 5, 11, 17, 20, 42)
+        obj_name = '   P/2025 K1'
+
+        horizons_id = determine_horizons_id(lines, obj_name, now)
+
+        self.assertEqual(expected_id, horizons_id)
+
     def test_bad_object(self):
         expected_id = None
         lines = ['Unknown target (20000P). Maybe try different id_type?']