diff --git a/src/synthesizer/emission_models/agn/models.py b/src/synthesizer/emission_models/agn/models.py
index 0ec9c969e..cc7c4499a 100644
--- a/src/synthesizer/emission_models/agn/models.py
+++ b/src/synthesizer/emission_models/agn/models.py
@@ -13,6 +13,7 @@
 
 """
 
+from synthesizer import exceptions
 from synthesizer.emission_models.base_model import BlackHoleEmissionModel
 
 
@@ -287,6 +288,12 @@ def __init__(
             **kwargs
 
         """
+        # Ensure the sum of covering fractions is less than 1
+        if covering_fraction_nlr + covering_fraction_blr > 1:
+            raise exceptions.InconsistentArguments(
+                "The sum of the covering fractions must be less than 1."
+            )
+
         # Create the child models
         nlr = NLRTransmittedEmission(
             grid=nlr_grid,
@@ -345,6 +352,12 @@ def __init__(
                 fraction of the BLR). Default is 0.1.
             **kwargs
         """
+        # Ensure the sum of covering fractions is less than 1
+        if covering_fraction_nlr + covering_fraction_blr > 1:
+            raise exceptions.InconsistentArguments(
+                "The sum of the covering fractions must be less than 1."
+            )
+
         BlackHoleEmissionModel.__init__(
             self,
             grid=grid,
@@ -494,6 +507,12 @@ def __init__(
             **kwargs
 
         """
+        # Ensure the sum of covering fractions is less than 1
+        if covering_fraction_nlr + covering_fraction_blr > 1:
+            raise exceptions.InconsistentArguments(
+                "The sum of the covering fractions must be less than 1."
+            )
+
         # Create the child models
         disc = DiscEmission(
             nlr_grid=nlr_grid,
diff --git a/src/synthesizer/emission_models/agn/unified_agn.py b/src/synthesizer/emission_models/agn/unified_agn.py
index 509b6fe50..184ff477d 100644
--- a/src/synthesizer/emission_models/agn/unified_agn.py
+++ b/src/synthesizer/emission_models/agn/unified_agn.py
@@ -23,6 +23,7 @@
 import numpy as np
 from unyt import deg
 
+from synthesizer import exceptions
 from synthesizer.emission_models.base_model import BlackHoleEmissionModel
 from synthesizer.sed import Sed
 
@@ -157,6 +158,12 @@ def __init__(
             **kwargs: Any additional keyword arguments to pass to the
                 BlackHoleEmissionModel.
         """
+        # Ensure the sum of covering fractions is less than 1
+        if covering_fraction_nlr + covering_fraction_blr > 1:
+            raise exceptions.InconsistentArguments(
+                "The sum of the covering fractions must be less than 1."
+            )
+
         # Get the incident istropic disc emission model
         self.disc_incident_isotropic = self._make_disc_incident_isotropic(
             nlr_grid,