diff --git a/src/Ionization/IonizationFactory.h b/src/Ionization/IonizationFactory.h
index 0fe22fd6b..597eb14af 100644
--- a/src/Ionization/IonizationFactory.h
+++ b/src/Ionization/IonizationFactory.h
@@ -18,36 +18,62 @@ class IonizationFactory
         Ionization *Ionize = NULL;
         std::string model = species->ionization_model_;
 
-        if (species->max_charge_ > (int)species->atomic_number_) {
-            ERROR("Charge > atomic_number for species " << species->name_);
-        }
-        if (species->particles->is_test) {
-            ERROR("Cannot ionize test species " << species->name_);
-        }
+        if( model == "tunnel" ) {
+            checkMaxCharge(species);
+            checkNotLaserEnvelopeModel(params);
+            Ionize = new IonizationTunnel<0>( params, species ); // The original model included in Smilei
+            
+        } else if( model == "tunnel_envelope_averaged" ) {
+            checkMaxCharge(species);
+            checkTestParticle(species);
+            if ( !params.Laser_Envelope_model ) {
+                ERROR( "The ionization model tunnel_envelope_averaged needs a laser envelope");
+            }
+
+            Ionize = new IonizationTunnelEnvelopeAveraged( params, species );
 
-        if (model == "tunnel_envelope_averaged") {
-            if (!params.Laser_Envelope_model) {
-                ERROR("The ionization model tunnel_envelope_averaged needs a laser envelope");
+         } else if( model == "from_rate" ) {
+            if ( species->max_charge_ > ( int ) species->maximum_charge_state_ ) {
+                ERROR( "For species '" << species->name_ << ": charge > maximum_charge_state" );
             }
-            Ionize = new IonizationTunnelEnvelopeAveraged(params, species);
-        } else if (params.Laser_Envelope_model) {
-            ERROR("The ionization model for species interacting with envelope is tunnel_envelope_averaged");
-        }
 
-        if (model == "from_rate") {
-            Ionize = new IonizationFromRate(params, species);
-        } else if (model == "tunnel") {
-            Ionize = new IonizationTunnel<0>(params, species); // Tunnel, the original included in Smilei
+            Ionize = new IonizationFromRate( params, species );
+
         } else if (model == "tunnel_full_PPT") {  
+            checkMaxCharge(species);
+            checkNotLaserEnvelopeModel(params);
             Ionize = new IonizationTunnel<1>(params, species); // FullPPT
         } else if (model == "tunnel_TL") {  
+            checkMaxCharge(species);
+            checkNotLaserEnvelopeModel(params);
             Ionize = new IonizationTunnel<2>(params, species); // Tong&Ling
         } else if (model == "tunnel_BSI") {  
+            checkMaxCharge(species);
+            checkNotLaserEnvelopeModel(params);
             Ionize = new IonizationTunnel<3>(params, species); // BSI
         }
 
         return Ionize;
     }
+           
+  private:
+    inline static void checkMaxCharge(const Species *species) {
+        if ( species->max_charge_ > ( int )species->atomic_number_ ) {
+            ERROR( "Charge > atomic_number for species " << species->name_ );
+        }
+    }
+
+    inline static void checkTestParticle(const Species *species) {
+        if( species->particles->is_test ) {
+            ERROR( "Cannot ionize test species " << species->name_ );
+        }
+    }
+
+    inline static void checkNotLaserEnvelopeModel(const Params &params) {
+        if ( params.Laser_Envelope_model ) {
+            ERROR( "The ionization model for species interacting with envelope is tunnel_envelope_averaged" );
+        }
+    }
 };
 
 #endif