diff --git a/lib/NGCP/Panel/Controller/Customer.pm b/lib/NGCP/Panel/Controller/Customer.pm
index 8698726cf5..5f95e7f687 100644
--- a/lib/NGCP/Panel/Controller/Customer.pm
+++ b/lib/NGCP/Panel/Controller/Customer.pm
@@ -367,7 +367,21 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
                 my $old_bprof_id = $billing_mapping->billing_profile_id;
                 $c->log->debug(">>>>>>>>>>> old bprof_id=$old_bprof_id");
                 my $old_prepaid = $billing_mapping->billing_profile->prepaid;
+                my $old_ext_id = $contract->external_id;
                 $contract->update($form->params);
+
+                if($contract->external_id ne $old_ext_id) {
+                    foreach my $sub($contract->voip_subscribers->all) {
+                        my $prov_sub = $sub->provisioning_voip_subscriber;
+                        next unless($prov_sub);
+                        NGCP::Panel::Utils::Subscriber::update_preferences(
+                            c => $c, 
+                            prov_subscriber => $prov_sub, 
+                            preferences => { ext_contract_id => $contract->external_id }
+                        );
+                    }
+                }
+
                 if($bprof_id != $old_bprof_id) {
                     $contract->billing_mappings->create({
                         billing_profile_id => $bprof_id,
@@ -573,6 +587,12 @@ sub subscriber_create :Chained('base') :PathPart('subscriber/create') :Args(0) {
                     $preferences->{display_name} = $form->params->{display_name}
                         if($form->params->{display_name});
                 }
+                if($c->stash->{contract}->external_id) {
+                    $preferences->{ext_contract_id} = $c->stash->{contract}->external_id;
+                }
+                if($c->stash->{external_id}) {
+                    $preferences->{ext_subscriber_id} = $c->stash->{external_id};
+                }
                 if($c->stash->{billing_mapping}->billing_profile->prepaid) {
                     $preferences->{prepaid} = 1;
                 }
diff --git a/lib/NGCP/Panel/Controller/Subscriber.pm b/lib/NGCP/Panel/Controller/Subscriber.pm
index 33e77d5c84..46c0bee543 100644
--- a/lib/NGCP/Panel/Controller/Subscriber.pm
+++ b/lib/NGCP/Panel/Controller/Subscriber.pm
@@ -206,11 +206,25 @@ sub create_list :Chained('sub_list') :PathPart('create') :Args(0) :Does(ACL) :AC
                             'value' => 1,
                         });
                 }
+                if(defined $billing_subscriber->external_id) {
+                    $voip_preferences->find({ 'attribute' => 'ext_subscriber_id' })
+                        ->voip_usr_preferences->create({ 
+                            'subscriber_id' => $prov_subscriber->id,
+                            'value' => $billing_subscriber->external_id,
+                        });
+                }
                 $voip_preferences->find({ 'attribute' => 'account_id' })
                     ->voip_usr_preferences->create({ 
                         'subscriber_id' => $prov_subscriber->id,
                         'value' => $prov_subscriber->contract->id,
                     });
+                if($contract->external_id) {
+                    $voip_preferences->find({ 'attribute' => 'ext_contract_id' })
+                        ->voip_usr_preferences->create({ 
+                            'subscriber_id' => $prov_subscriber->id,
+                            'value' => $contract->external_id,
+                        });
+                }
                 $voip_preferences->find({ 'attribute' => 'ac' })
                     ->voip_usr_preferences->create({ 
                         'subscriber_id' => $prov_subscriber->id,
@@ -1955,6 +1969,15 @@ sub edit_master :Chained('master') :PathPart('edit') :Args(0) :Does(ACL) :ACLDet
                     status => $form->params->{status},
                     external_id => $form->params->{external_id},
                 });
+                if(defined $subscriber->external_id) {
+                    my $ext_pref = NGCP::Panel::Utils::Preferences::get_usr_preference_rs(
+                        c => $c, attribute => 'ext_subscriber_id', prov_subscriber => $prov_subscriber);
+                    unless($ext_pref->first) {
+                        $ext_pref->create({ value => $subscriber->external_id });
+                    } else {
+                        $ext_pref->first->update({ value => $subscriber->external_id });
+                    }
+                }
                 if($subscriber->status eq 'locked') {
                     $form->values->{lock} = 4; # update lock below
                 } elsif($old_status eq 'locked' && $subscriber->status eq 'active') {
diff --git a/lib/NGCP/Panel/Role/API/Customers.pm b/lib/NGCP/Panel/Role/API/Customers.pm
index 0d99ad8a9c..fb1ce5ec1c 100644
--- a/lib/NGCP/Panel/Role/API/Customers.pm
+++ b/lib/NGCP/Panel/Role/API/Customers.pm
@@ -177,8 +177,22 @@ sub update_customer {
         }
     }
 
+    my $old_ext_id = $customer->external_id;
+
     $customer->update($resource);
 
+    if($customer->external_id ne $old_ext_id) {
+        foreach my $sub($customer->voip_subscribers->all) {
+            my $prov_sub = $sub->provisioning_voip_subscriber;
+            next unless($prov_sub);
+            NGCP::Panel::Utils::Subscriber::update_preferences(
+                c => $c,
+                prov_subscriber => $prov_sub,
+                preferences => { ext_contract_id => $customer->external_id }
+            );
+        }
+    }
+
     if($old_resource->{status} ne $resource->{status}) {
         if($customer->id == 1) {
             $self->error($c, HTTP_FORBIDDEN, "Cannot set customer status to '".$resource->{status}."' for customer id '1'");
diff --git a/lib/NGCP/Panel/Role/API/Subscribers.pm b/lib/NGCP/Panel/Role/API/Subscribers.pm
index c153769771..3670be3e7f 100644
--- a/lib/NGCP/Panel/Role/API/Subscribers.pm
+++ b/lib/NGCP/Panel/Role/API/Subscribers.pm
@@ -60,6 +60,14 @@ sub transform_resource {
             push @{ $resource{alias_numbers} }, $alias;
         }
     }
+
+    my $pref = NGCP::Panel::Utils::Preferences::get_usr_preference_rs(
+        c => $c, attribute => 'lock', 
+        prov_subscriber => $item->provisioning_voip_subscriber);
+    if($pref->first) {
+        $resource{lock} = $pref->first->value;
+    }
+
     $resource{customer_id} = int(delete $resource{contract_id});
     $resource{id} = int($item->id);
     $resource{domain} = $item->domain->domain;
@@ -264,6 +272,12 @@ sub prepare_resource {
             $preferences->{cloud_pbx_base_cli} = $base_number->{cc} . $base_number->{ac} . $base_number->{sn};
         }
     }
+    if(exists $resource->{external_id}) {
+        $preferences->{ext_subscriber_id} = $resource->{external_id};
+    }
+    if(defined $customer->external_id) {
+        $preferences->{ext_contract_id} = $customer->external_id;
+    }
 
     my $billing_profile = $self->get_billing_profile($c, $customer);
     return unless($billing_profile);
@@ -320,6 +334,7 @@ sub prepare_resource {
         alias_numbers => $alias_numbers,
         preferences => $preferences,
     };
+
     return $r;
 }
 
@@ -347,16 +362,18 @@ sub update_item {
             return;
         }
     }
-    try {
-        NGCP::Panel::Utils::Subscriber::lock_provisoning_voip_subscriber(
-            c => $c,
-            prov_subscriber => $subscriber->provisioning_voip_subscriber,
-            level => $resource->{lock},
-        );
-    } catch($e) {
-        $c->log->error("failed to lock subscriber id ".$subscriber->id." with level ".$resource->{lock});
-        $self->error($c, HTTP_INTERNAL_SERVER_ERROR, "Failed to update subscriber lock");
-        return;
+    if(defined $resource->{lock}) {
+        try {
+            NGCP::Panel::Utils::Subscriber::lock_provisoning_voip_subscriber(
+                c => $c,
+                prov_subscriber => $subscriber->provisioning_voip_subscriber,
+                level => $resource->{lock},
+            );
+        } catch($e) {
+            $c->log->error("failed to lock subscriber id ".$subscriber->id." with level ".$resource->{lock});
+            $self->error($c, HTTP_INTERNAL_SERVER_ERROR, "Failed to update subscriber lock");
+            return;
+        }
     }
 
     NGCP::Panel::Utils::Subscriber::update_subscriber_numbers(
@@ -385,6 +402,11 @@ sub update_item {
     $subscriber->update($billing_res);
     $subscriber->provisioning_voip_subscriber->update($provisioning_res);
     $subscriber->discard_changes;
+    NGCP::Panel::Utils::Subscriber::update_preferences(
+        c => $c, 
+        prov_subscriber => $subscriber->provisioning_voip_subscriber,
+        preferences => $preferences
+    );
 
     # TODO: status handling (termination, ...)
 
diff --git a/lib/NGCP/Panel/Utils/Subscriber.pm b/lib/NGCP/Panel/Utils/Subscriber.pm
index 847bb4bc58..aa4ece8b9a 100644
--- a/lib/NGCP/Panel/Utils/Subscriber.pm
+++ b/lib/NGCP/Panel/Utils/Subscriber.pm
@@ -198,19 +198,10 @@ sub create_subscriber {
         $preferences->{cli} = $cli
             if(defined $cli);
 
-        foreach my $k(keys %{ $preferences } ) {
-            my $pref = NGCP::Panel::Utils::Preferences::get_usr_preference_rs(
-                c => $c, attribute => $k, prov_subscriber => $prov_subscriber);
-            if($pref->first && $pref->first->attribute->max_occur == 1) {
-                $pref->first->update({ 
-                    'value' => $preferences->{$k},
-                });
-            } else {
-                $pref->create({ 
-                    'value' => $preferences->{$k},
-                });
-            }
-        }
+        update_preferences(c => $c, 
+            prov_subscriber => $prov_subscriber, 
+            preferences => $preferences
+        );
 
         $schema->resultset('voicemail_users')->create({
             customer_id => $uuid_string,
@@ -230,6 +221,27 @@ sub create_subscriber {
     });
 }
 
+sub update_preferences {
+    my (%params) = @_;
+    my $c = $params{c};
+    my $prov_subscriber = $params{prov_subscriber};
+    my $preferences = $params{preferences};
+
+    foreach my $k(keys %{ $preferences } ) {
+        my $pref = NGCP::Panel::Utils::Preferences::get_usr_preference_rs(
+            c => $c, attribute => $k, prov_subscriber => $prov_subscriber);
+        if($pref->first && $pref->first->attribute->max_occur == 1) {
+            $pref->first->update({ 
+                'value' => $preferences->{$k},
+            });
+        } else {
+            $pref->create({ 
+                'value' => $preferences->{$k},
+            });
+        }
+    }
+}
+
 sub get_custom_subscriber_struct {
     my %params = @_;
 
@@ -527,9 +539,11 @@ sub update_subscriber_numbers {
         subscriber_id => undef,
         reseller_id => undef,
     });
-    $prov_subs->voip_dbaliases->search({
-        id => { 'not in' => \@dbnums },
-    })->delete;
+    if($prov_subs) {
+        $prov_subs->voip_dbaliases->search({
+            id => { 'not in' => \@dbnums },
+        })->delete;
+    }
 
     return;
 }