diff --git a/lib/NGCP/Panel/Controller/API/LnpCarriersItem.pm b/lib/NGCP/Panel/Controller/API/LnpCarriersItem.pm
index df0acd8505..07c235ee52 100644
--- a/lib/NGCP/Panel/Controller/API/LnpCarriersItem.pm
+++ b/lib/NGCP/Panel/Controller/API/LnpCarriersItem.pm
@@ -100,7 +100,7 @@ sub PATCH :Allow {
         last unless $preference;
 
         my $json = $self->get_valid_patch_data(
-            c => $c, 
+            c => $c,
             id => $id,
             media_type => 'application/json-patch+json',
         );
@@ -115,7 +115,7 @@ sub PATCH :Allow {
         my $form = $self->get_form($c);
         $item = $self->update_item($c, $item, $old_resource, $resource, $form);
         last unless $item;
-        
+
         $guard->commit;
 
         if ('minimal' eq $preference) {
@@ -156,7 +156,7 @@ sub PUT :Allow {
         $item = $self->update_item($c, $item, $old_resource, $resource, $form);
         last unless $item;
 
-        $guard->commit; 
+        $guard->commit;
 
         if ('minimal' eq $preference) {
             $c->response->status(HTTP_NO_CONTENT);
@@ -182,6 +182,12 @@ sub DELETE :Allow {
     {
         my $item = $self->item_by_id($c, $id);
         last unless $self->resource_exists($c, lnpcarrier => $item);
+        my $number_count = $item->lnp_numbers->count;
+        if ($number_count > 0) {
+            $c->log->error("failed to delete lnp carrier, there are still $number_count lnp numbers linked to it.");
+            $self->error($c, HTTP_INTERNAL_SERVER_ERROR, "Failed to delete lnp carrier.");
+            last;
+        }
         $item->delete;
 
         $guard->commit;
diff --git a/lib/NGCP/Panel/Controller/API/LnpNumbers.pm b/lib/NGCP/Panel/Controller/API/LnpNumbers.pm
index 1302a1cf3f..c0342cd759 100644
--- a/lib/NGCP/Panel/Controller/API/LnpNumbers.pm
+++ b/lib/NGCP/Panel/Controller/API/LnpNumbers.pm
@@ -128,7 +128,7 @@ sub GET :Allow {
         $hal->resource({
             total_count => $total_count,
         });
-        my $response = HTTP::Response->new(HTTP_OK, undef, 
+        my $response = HTTP::Response->new(HTTP_OK, undef,
             HTTP::Headers->new($hal->http_headers(skip_links => 1)), $hal->as_json);
         $c->response->headers($response->headers);
         $c->response->body($response->content);
@@ -164,7 +164,7 @@ sub POST :Allow {
         my $schema = $c->model('DB');
         my $resource;
         my $data = $self->get_valid_raw_post_data(
-            c => $c, 
+            c => $c,
             media_type => [qw#application/json text/csv#],
         );
         last unless $data;
@@ -233,27 +233,20 @@ sub POST :Allow {
 
             my $carrier = $c->model('DB')->resultset('lnp_providers')->find($resource->{lnp_provider_id});
             unless($carrier) {
-                $c->log->error("invalid carrier_id '$$resource{lnp_provider_id}'"); # TODO: user, message, trace, ...
-                $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "LNP carrier_id does not exist");
+                $c->log->error("invalid carrier_id '$$resource{lnp_provider_id}'");
+                $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "lnp carrier_id does not exist");
                 last;
             }
-
-
-            my $item;
-
-=pod
-            # for now numbers can be inserted duplicated, so don't check
-            $item = $c->model('DB')->resultset('lnp_numbers')->find({
-                lnp_provider_id => $resource->{lnp_provider_id},
-                number => $resource->{number},
-            });
-            if($item) {
-                $c->log->error("lnp number with number '$$resource{number}' already exists for carrier_id '$$resource{lnp_provider_id}'"); # TODO: user, message, trace, ...
-                $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "LNP number with this number already exists for this LNP carrier");
+            if ($c->model('DB')->resultset('lnp_numbers')->search({
+                    lnp_provider_id => $carrier->id,
+                    number => $resource->{number}
+                },undef)->count > 0) {
+                $c->log->error("LNP number '$$resource{number}' already defined for carrier_id '$$resource{lnp_provider_id}'");
+                $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "lnp number already exists for lnp carrier");
                 last;
             }
-=cut
 
+            my $item;
             try {
                 $item = $c->model('DB')->resultset('lnp_numbers')->create($resource);
             } catch($e) {
diff --git a/lib/NGCP/Panel/Controller/Billing.pm b/lib/NGCP/Panel/Controller/Billing.pm
index 00e35aefa9..a0eaa33777 100644
--- a/lib/NGCP/Panel/Controller/Billing.pm
+++ b/lib/NGCP/Panel/Controller/Billing.pm
@@ -312,10 +312,10 @@ sub terminate :Chained('base') :PathPart('terminate') :Args(0) {
     try {
         #todo: putting the profile fetch into a transaction wouldn't help since the count columns a prone to phantom reads...
         unless($profile->get_column('contract_cnt') == 0) {
-            die('Cannnot terminate billing profile that is still used in profile mappings');
+            die(['Cannnot terminate billing profile that is still used in profile mappings', "showdetails"]);
         }
         unless($profile->get_column('package_cnt') == 0) {
-            die('Cannnot terminate billing profile that is still used in profile packages');
+            die(['Cannnot terminate billing profile that is still used in profile packages', "showdetails"]);
         }
         $profile->update({
             status => 'terminated',
diff --git a/lib/NGCP/Panel/Controller/Customer.pm b/lib/NGCP/Panel/Controller/Customer.pm
index 7fbe99f8c4..446adc2a05 100644
--- a/lib/NGCP/Panel/Controller/Customer.pm
+++ b/lib/NGCP/Panel/Controller/Customer.pm
@@ -1062,7 +1062,7 @@ sub topup_cash :Chained('base_restricted') :PathPart('balance/topupcash') :Args(
                     entities => $entities,
                     err_code => sub {
                         my ($err) = @_;
-                        die($err);
+                        die([$err, "showdetails"]);
                         },
                     );
 
@@ -1154,7 +1154,7 @@ sub topup_voucher :Chained('base_restricted') :PathPart('balance/topupvoucher')
                     entities => $entities,
                     err_code => sub {
                         my ($err) = @_;
-                        die($err);
+                        die([$err, "showdetails"]);
                         },
                     );
 
diff --git a/lib/NGCP/Panel/Controller/Lnp.pm b/lib/NGCP/Panel/Controller/Lnp.pm
index 15356e62c3..8bf665ee06 100644
--- a/lib/NGCP/Panel/Controller/Lnp.pm
+++ b/lib/NGCP/Panel/Controller/Lnp.pm
@@ -32,6 +32,9 @@ sub list :Chained('/') :PathPart('lnp') :CaptureArgs(0) {
         { name => "prefix", "search" => 1, "title" => $c->loc("Prefix") },
         { name => "authoritative", "search" => 0, "title" => $c->loc("Authoritative") },
         { name => "skip_rewrite", "search" => 0, "title" => $c->loc("Skip Rewrite") },
+        #better leave this out for performance reasons:
+        #{ name => "numbers_count", "search" => 0, "title" => $c->loc("#Numbers"),
+        #  literal_sql=>"select count(n.id) from `billing`.`lnp_numbers` n where n.`lnp_provider_id` = `me`.`id`" },
     ]);
 
     my $number_rs = $c->model('DB')->resultset('lnp_numbers');
@@ -77,7 +80,7 @@ sub carrier_base :Chained('list') :PathPart('carrier') :CaptureArgs(1) {
         NGCP::Panel::Utils::Message::error(
             c => $c,
             data => { id => $carrier_id },
-            desc  => $c->loc('Invalid lnp carrier id detected!'),
+            desc  => $c->loc('Invalid LNP carrier id detected!'),
         );
         $c->flash(carrier_messages => delete $c->flash->{messages});
         $c->response->redirect($c->uri_for());
@@ -193,10 +196,20 @@ sub carrier_delete :Chained('carrier_base') :PathPart('delete') :Args(0) {
     my ($self, $c) = @_;
     my $carrier = $c->stash->{carrier_result};
 
+    my $number_count = $carrier->lnp_numbers->count;
+    if ($number_count > 0) {
+        NGCP::Panel::Utils::Message::error(
+            c => $c,
+            desc  => $c->loc("$number_count lnp numbers still linked to LNP carrier."),
+        );
+        $c->flash(carrier_messages => delete $c->flash->{messages});
+        NGCP::Panel::Utils::Navigation::back_or($c, $c->uri_for('/lnp'));
+        return;
+    }
+
     try {
         my $schema = $c->model('DB');
         $schema->txn_do(sub {
-            $carrier->lnp_numbers->delete;
             $carrier->delete;
         });
         NGCP::Panel::Utils::Message::info(
@@ -210,7 +223,7 @@ sub carrier_delete :Chained('carrier_base') :PathPart('delete') :Args(0) {
             c => $c,
             error => $e,
             data  => $c->stash->{carrier},
-            desc  => $c->loc('Failed to terminate LNP carrier'),
+            desc  => $c->loc('Failed to delete LNP carrier'),
         );
         $c->flash(carrier_messages => delete $c->flash->{messages});
     };
@@ -224,7 +237,7 @@ sub number_base :Chained('list') :PathPart('number') :CaptureArgs(1) {
         NGCP::Panel::Utils::Message::error(
             c => $c,
             data => { id => $number_id },
-            desc  => $c->loc('Invalid lnp number id detected!'),
+            desc  => $c->loc('Invalid LNP number id detected!'),
         );
         $c->flash(number_messages => delete $c->flash->{messages});
         $c->response->redirect($c->uri_for());
@@ -271,11 +284,35 @@ sub number_edit :Chained('number_base') :PathPart('edit') {
         back_uri => $c->req->uri,
     );
     if($posted && $form->validated) {
+        $form->values->{lnp_provider_id} = $form->values->{lnp_provider}{id};
+        delete $form->values->{lnp_provider};
+        my $carrier = $c->model('DB')->resultset('lnp_providers')->find($form->values->{lnp_provider_id});
+        unless($carrier) {
+            NGCP::Panel::Utils::Message::error(
+                c => $c,
+                data => { id => $form->values->{lnp_provider_id} },
+                    desc  => $c->loc('Invalid LNP provider id detected!'),
+                );
+            $c->flash(number_messages => delete $c->flash->{messages});
+            NGCP::Panel::Utils::Navigation::back_or($c, $c->uri_for('/lnp'));
+            return;
+        }
+        if ($c->model('DB')->resultset('lnp_numbers')->search({
+                lnp_provider_id => $carrier->id,
+                number => $form->values->{number}
+            },undef)->count > 0) {
+            NGCP::Panel::Utils::Message::error(
+                c => $c,
+                data => { number => $form->values->{number} },
+                desc  => $c->loc("LNP number '" . $form->values->{number} . "' already defined for LNP provider '" . $carrier->name . "'!"),
+            );
+            $c->flash(number_messages => delete $c->flash->{messages});
+            NGCP::Panel::Utils::Navigation::back_or($c, $c->uri_for('/lnp'));
+            return;
+        }
         try {
             my $schema = $c->model('DB');
             $schema->txn_do(sub {
-                $form->values->{lnp_provider_id} = $form->values->{lnp_provider}{id};
-                delete $form->values->{lnp_provider};
                 if(length $form->values->{start}) {
                     $form->values->{start} .= 'T00:00:00';
                 } else {
@@ -287,15 +324,6 @@ sub number_edit :Chained('number_base') :PathPart('edit') {
                     $form->values->{end} = undef;
                 }
                 $form->values->{routing_number} = undef unless(length $form->values->{routing_number});
-                my $carrier = $c->model('DB')->resultset('lnp_providers')->find($form->values->{lnp_provider_id});
-                unless($carrier) {
-                    NGCP::Panel::Utils::Message::error(
-                        c => $c,
-                        data => { id => $form->values->{lnp_provider_id} },
-                        desc  => $c->loc('Invalid lnp provider id detected!'),
-                    );
-                    $c->flash(number_messages => delete $c->flash->{messages});
-                }
                 $c->stash->{number_result}->update($form->values);
             });
 
@@ -339,18 +367,33 @@ sub number_create :Chained('list') :PathPart('number_create') :Args(0) {
         back_uri => $c->req->uri,
     );
     if($posted && $form->validated) {
+        $form->values->{lnp_provider_id} = $form->values->{lnp_provider}{id};
+        delete $form->values->{lnp_provider};
+        my $carrier = $c->model('DB')->resultset('lnp_providers')->find($form->values->{lnp_provider_id});
+        unless($carrier) {
+            NGCP::Panel::Utils::Message::error(
+                c => $c,
+                data => { id => $form->values->{lnp_provider_id} },
+                desc  => $c->loc('Invalid LNP provider id detected!'),
+            );
+            $c->flash(number_messages => delete $c->flash->{messages});
+            NGCP::Panel::Utils::Navigation::back_or($c, $c->uri_for('/lnp'));
+            return;
+        }
+        if ($c->model('DB')->resultset('lnp_numbers')->search({
+                lnp_provider_id => $carrier->id,
+                number => $form->values->{number}
+            },undef)->count > 0) {
+            NGCP::Panel::Utils::Message::error(
+                c => $c,
+                data => { number => $form->values->{number} },
+                desc  => $c->loc("LNP number '" . $form->values->{number} . "' already defined for LNP provider '" . $carrier->name . "'!"),
+            );
+            $c->flash(number_messages => delete $c->flash->{messages});
+            NGCP::Panel::Utils::Navigation::back_or($c, $c->uri_for('/lnp'));
+            return;
+        }
         try {
-            $form->values->{lnp_provider_id} = $form->values->{lnp_provider}{id};
-            delete $form->values->{lnp_provider};
-            my $carrier = $c->model('DB')->resultset('lnp_providers')->find($form->values->{lnp_provider_id});
-            unless($carrier) {
-                NGCP::Panel::Utils::Message::error(
-                    c => $c,
-                    data => { id => $form->values->{lnp_provider_id} },
-                    desc  => $c->loc('Invalid lnp provider id detected!'),
-                );
-                $c->flash(number_messages => delete $c->flash->{messages});
-            }
             if(length $form->values->{start}) {
                 $form->values->{start} .= 'T00:00:00';
             } else {
@@ -495,4 +538,3 @@ sub numbers_download :Chained('list') :PathPart('download') :Args(0) {
 __PACKAGE__->meta->make_immutable;
 
 1;
-
diff --git a/lib/NGCP/Panel/Controller/Network.pm b/lib/NGCP/Panel/Controller/Network.pm
index 7738a9864d..4d7ea928b8 100644
--- a/lib/NGCP/Panel/Controller/Network.pm
+++ b/lib/NGCP/Panel/Controller/Network.pm
@@ -92,7 +92,7 @@ sub create :Chained('network_list') :PathPart('create') :Args(0) {
             'reseller.create' => $c->uri_for('/reseller/create'),
         },
         back_uri => $c->req->uri,
-    );    
+    );
     if($posted && $form->validated) {
         try {
             my $reseller_id = ($c->user->is_superuser ? $form->values->{reseller}{id} : $c->user->reseller_id);
@@ -108,7 +108,7 @@ sub create :Chained('network_list') :PathPart('create') :Args(0) {
                 delete $c->session->{created_objects}->{reseller};
                 $c->session->{created_objects}->{network} = { id => $bn->id };
             });
-            
+
             NGCP::Panel::Utils::Message::info(
                 c => $c,
                 desc => $c->loc('Billing Network successfully created'),
@@ -179,7 +179,7 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
 
         try {
             $c->model('DB')->schema->txn_do( sub {
-                
+
                 $c->stash->{'network_result'}->update({
                     name => $form->values->{name},
                     description => $form->values->{description},
@@ -192,7 +192,7 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
             NGCP::Panel::Utils::Message::info(
                 c => $c,
                 desc  => $c->loc('Billing network successfully updated'),
-            );            
+            );
         } catch ($e) {
             NGCP::Panel::Utils::Message::error(
                 c => $c,
@@ -219,10 +219,10 @@ sub terminate :Chained('base') :PathPart('terminate') :Args(0) {
     try {
         #todo: putting the network fetch into a transaction wouldn't help since the count columns a prone to phantom reads...
         unless($network->get_column('contract_cnt') == 0) {
-            die('Cannnot terminate billing network that is still used in profile mappings');
+            die(['Cannnot terminate billing network that is still used in profile mappings', "showdetails"]);
         }
         unless($network->get_column('package_cnt') == 0) {
-            die('Cannnot terminate billing network that is still used in profile packages');
+            die(['Cannnot terminate billing network that is still used in profile packages', "showdetails"]);
         }
         $network->update({
             status => 'terminated',
diff --git a/lib/NGCP/Panel/Controller/Package.pm b/lib/NGCP/Panel/Controller/Package.pm
index 7b100fa239..5167fb51d0 100644
--- a/lib/NGCP/Panel/Controller/Package.pm
+++ b/lib/NGCP/Panel/Controller/Package.pm
@@ -93,7 +93,7 @@ sub create :Chained('package_list') :PathPart('create') :Args(0) {
             'reseller.create' => $c->uri_for('/reseller/create'),
         },
         back_uri => $c->req->uri,
-    );    
+    );
     if($posted && $form->validated) {
         try {
             $form->values->{reseller_id} = ($c->user->is_superuser ? $form->values->{reseller}{id} : $c->user->reseller_id);
@@ -106,16 +106,16 @@ sub create :Chained('package_list') :PathPart('create') :Args(0) {
             my @mappings_to_create = ();
             push(@mappings_to_create,@{delete $form->values->{initial_profiles}});
             push(@mappings_to_create,@{delete $form->values->{underrun_profiles}});
-            push(@mappings_to_create,@{delete $form->values->{topup_profiles}});            
+            push(@mappings_to_create,@{delete $form->values->{topup_profiles}});
             $c->model('DB')->schema->txn_do( sub {
                 my $profile_package = $c->model('DB')->resultset('profile_packages')->create($form->values);
                 foreach my $mapping (@mappings_to_create) {
-                    $profile_package->profiles->create($mapping); 
+                    $profile_package->profiles->create($mapping);
                 }
                 delete $c->session->{created_objects}->{reseller};
                 $c->session->{created_objects}->{package} = { id => $profile_package->id };
             });
-            
+
             NGCP::Panel::Utils::Message::info(
                 c => $c,
                 desc => $c->loc('Profile package successfully created'),
@@ -129,7 +129,7 @@ sub create :Chained('package_list') :PathPart('create') :Args(0) {
         }
         NGCP::Panel::Utils::Navigation::back_or($c, $c->uri_for('/package'));
     }
-    
+
     $c->stash(
         close_target => $c->uri_for,
         create_flag => 1,
@@ -151,7 +151,7 @@ sub base :Chained('/package/package_list') :PathPart('') :CaptureArgs(1) {
         $c->detach;
         return;
     }
-    
+
     my $res = $c->stash->{package_rs}->find($package_id);
     unless(defined($res)) {
         NGCP::Panel::Utils::Message::error(
@@ -162,7 +162,7 @@ sub base :Chained('/package/package_list') :PathPart('') :CaptureArgs(1) {
         $c->detach;
         return;
     }
-    
+
     $c->stash(package        => {$res->get_inflated_columns},
               initial_profiles => [ map { { $_->get_inflated_columns }; } $res->initial_profiles->all ],
               underrun_profiles => [ map { { $_->get_inflated_columns }; } $res->underrun_profiles->all ],
@@ -182,7 +182,7 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
     $params->{reseller}{id} = delete $params->{reseller_id};
     foreach(qw/balance_interval timely_duration/){
         $params->{$_} = { unit => delete $params->{$_.'_unit'}, value => delete $params->{$_.'_value'} };
-    }    
+    }
     $params = merge($params, $c->session->{created_objects});
     $form->process(
         posted => $posted,
@@ -197,7 +197,7 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
             'reseller.create' => $c->uri_for('/reseller/create'),
         },
         back_uri => $c->req->uri,
-    );        
+    );
     if($posted && $form->validated) {
         try {
             foreach(qw/balance_interval timely_duration/){
@@ -208,19 +208,19 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
             my @mappings_to_create = ();
             push(@mappings_to_create,@{delete $form->values->{initial_profiles}});
             push(@mappings_to_create,@{delete $form->values->{underrun_profiles}});
-            push(@mappings_to_create,@{delete $form->values->{topup_profiles}});            
+            push(@mappings_to_create,@{delete $form->values->{topup_profiles}});
             $c->model('DB')->schema->txn_do( sub {
 
                 my $profile_package = $c->stash->{'package_result'}->update($form->values);
-                $profile_package->profiles->delete;        
+                $profile_package->profiles->delete;
                 foreach my $mapping (@mappings_to_create) {
-                    $profile_package->profiles->create($mapping); 
+                    $profile_package->profiles->create($mapping);
                 }
             });
             NGCP::Panel::Utils::Message::info(
                 c => $c,
                 desc  => $c->loc('Profile package successfully updated'),
-            );            
+            );
         } catch ($e) {
             NGCP::Panel::Utils::Message::error(
                 c => $c,
@@ -228,11 +228,11 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
                 desc  => $c->loc('Failed to update profile package'),
             );
         }
-    
+
         NGCP::Panel::Utils::Navigation::back_or($c, $c->uri_for('/package'));
-    
+
     }
-    
+
     $c->stash(
         close_target => $c->uri_for,
         edit_flag => 1,
@@ -247,12 +247,12 @@ sub delete :Chained('base') :PathPart('delete') :Args(0) {
     try {
         #todo: putting the package fetch into a transaction wouldn't help since the count columns a prone to phantom reads...
         unless($package->get_column('contract_cnt') == 0) {
-            die('Cannnot delete profile package that is still assigned to contracts');
+            die(['Cannnot delete profile package that is still assigned to contracts', "showdetails"]);
         }
         unless($package->get_column('voucher_cnt') == 0) {
-            die('Cannnot delete profile package that is assigned to vouchers');
+            die(['Cannnot delete profile package that is assigned to vouchers', "showdetails"]);
         }
-        
+
         $package->delete;
         NGCP::Panel::Utils::Message::info(
             c => $c,
@@ -294,7 +294,7 @@ sub details_base :Chained('/') :PathPart('package') :CaptureArgs(1) {
 
     my $dispatch_to = '_package_resultset_' . $c->user->roles;
     my $package_rs = $self->$dispatch_to($c);
-    
+
     unless($package_id && is_int($package_id)) {
         $package_id //= '';
         NGCP::Panel::Utils::Message::error(
@@ -306,7 +306,7 @@ sub details_base :Chained('/') :PathPart('package') :CaptureArgs(1) {
         $c->detach;
         return;
     }
-    
+
     my $res = $package_rs->find($package_id);
     unless(defined($res)) {
         NGCP::Panel::Utils::Message::error(
@@ -328,8 +328,8 @@ sub details_base :Chained('/') :PathPart('package') :CaptureArgs(1) {
     ]);
     $c->stash->{voucher_dt_columns} = NGCP::Panel::Utils::Datatables::set_columns($c, [
         NGCP::Panel::Utils::Voucher::get_datatable_cols($c,1)
-    ]);    
-    
+    ]);
+
     $c->stash(package_result => $res);
 }
 
diff --git a/lib/NGCP/Panel/Role/API/LnpNumbers.pm b/lib/NGCP/Panel/Role/API/LnpNumbers.pm
index b8576b2bcf..514a5130a9 100644
--- a/lib/NGCP/Panel/Role/API/LnpNumbers.pm
+++ b/lib/NGCP/Panel/Role/API/LnpNumbers.pm
@@ -92,19 +92,14 @@ sub update_item {
         $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "LNP carrier_id does not exist");
         return;
     }
-
-=pod
-    # for now numbers can be inserted duplicated, so don't check
-    my $dup_item = $c->model('DB')->resultset('lnp_numbers')->find({
-        lnp_provider_id => $resource->{lnp_provider_id},
-        number => $resource->{number},
-    });
-    if($dup_item && $dup_item->id != $item->id) {
-        $c->log->error("lnp number with number '$$resource{number}' already exists for carrier_id '$$resource{lnp_provider_id}'"); # TODO: user, message, trace, ...
-        $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "LNP number with this number already exists for this carrier");
+    if ($c->model('DB')->resultset('lnp_numbers')->search({
+            lnp_provider_id => $carrier->id,
+            number => $resource->{number}
+        },undef)->count > 0) {
+        $c->log->error("LNP number '$$resource{number}' already defined for carrier_id '$$resource{lnp_provider_id}'");
+        $self->error($c, HTTP_UNPROCESSABLE_ENTITY, "lnp number already exists for lnp carrier");
         return;
     }
-=cut
 
     $resource->{start} ||= undef;
     if($resource->{start} && $resource->{start} =~ /^\d{4}-\d{2}-\d{2}$/) {
diff --git a/t/api-rest/api-lnp.t b/t/api-rest/api-lnp.t
new file mode 100644
index 0000000000..3eb971ccb8
--- /dev/null
+++ b/t/api-rest/api-lnp.t
@@ -0,0 +1,204 @@
+use Sipwise::Base;
+use Net::Domain qw(hostfqdn);
+use LWP::UserAgent;
+use JSON qw();
+use Test::More;
+
+use warnings;
+
+my $is_local_env = 0;
+
+my $uri = $ENV{CATALYST_SERVER} || ('https://'.hostfqdn.':4443');
+my ($netloc) = ($uri =~ m!^https?://(.*)/?.*$!);
+
+my ($ua, $req, $res);
+$ua = LWP::UserAgent->new;
+
+$ua->ssl_opts(
+        verify_hostname => 0,
+        SSL_verify_mode => 0,
+    );
+my $user = $ENV{API_USER} // 'administrator';
+my $pass = $ENV{API_PASS} // 'administrator';
+$ua->credentials($netloc, "api_admin_http", $user, $pass);
+
+#$ua->add_handler("request_send",  sub {
+#    my ($request, $ua, $h) = @_;
+#    print $request->method . ' ' . $request->uri . "\n" . ($request->content ? $request->content . "\n" : '') unless $request->header('authorization');
+#    return undef;
+#});
+#$ua->add_handler("response_done", sub {
+#    my ($response, $ua, $h) = @_;
+#    print $response->decoded_content . "\n" if $response->code != 401;
+#    return undef;
+#});
+
+my $t = time;
+
+my %carrier_map = ();
+my %number_map = ();
+
+{ #regular case
+    my $carrier1 = _create_lnp_provider();
+    my $number1 = _create_lnp_number($carrier1, number => '123');
+    my $number2 = _create_lnp_number($carrier1, number => '456');
+    _delete_lnp_number($number1);
+    _delete_lnp_number($number2);
+    _delete_lnp_provider($carrier1);
+}
+
+{ #delete provider with numbers left:
+    my $carrier1 = _create_lnp_provider();
+    my $number1 = _create_lnp_number($carrier1, number => '123');
+    _delete_lnp_provider($carrier1, 500);
+}
+
+{ #unique number - insert:
+    my $carrier1 = _create_lnp_provider();
+    my $number1 = _create_lnp_number($carrier1, number => '123');
+    my $number2 = _create_lnp_number($carrier1, number => '123', expected_code => 422);
+    #_delete_lnp_provider($carrier1, expected_code => 500);
+}
+
+{ #unique number - update:
+    my $carrier1 = _create_lnp_provider();
+    my $number1 = _create_lnp_number($carrier1, number => '123');
+    my $number2 = _create_lnp_number($carrier1, number => '1234');
+    _update_lnp_number($number2, number => '123', expected_code => 422);
+}
+
+#todo: multithread insert testcase
+
+sub _create_lnp_number {
+
+    my $carrier = shift;
+    my (%further_opts) = @_;
+    my $expected_code = delete $further_opts{expected_code} // 201;
+    $req = HTTP::Request->new('POST', $uri.'/api/lnpnumbers/');
+    $req->header('Content-Type' => 'application/json');
+    $req->content(JSON::to_json({
+        carrier_id => $carrier->{id},
+        number => 'test'.$t,
+        %further_opts,
+    }));
+    $res = $ua->request($req);
+    if ($expected_code eq '201') {
+        is($res->code, 201, "create test lnp number");
+        $req = HTTP::Request->new('GET', $uri.'/'.$res->header('Location'));
+        $res = $ua->request($req);
+        is($res->code, 200, "fetch test lnp number");
+        my $number = JSON::from_json($res->decoded_content);
+        $number_map{$carrier->{id}} = $number;
+        return $number;
+    } else {
+        is($res->code, $expected_code, "create test lnp number returns $expected_code");
+        return undef;
+    }
+
+}
+
+sub _update_lnp_number {
+
+    my $number = shift;
+    my (%further_opts) = @_;
+    my $expected_code = delete $further_opts{expected_code} // 200;
+    my $url = $uri.'/api/lnpnumbers/'.$number->{id};
+    $req = HTTP::Request->new('PUT', $url);
+    $req->header('Content-Type' => 'application/json');
+    $req->header('Prefer' => 'return=representation');
+    $req->content(JSON::to_json({
+        %$number,
+        %further_opts,
+    }));
+    $res = $ua->request($req);
+    if ($expected_code eq '200') {
+        is($res->code, 200, "update test lnp number");
+        $number = JSON::from_json($res->decoded_content);
+        $number_map{$number->{id}} = $number;
+        return $number;
+    } else {
+        is($res->code, $expected_code, "update test lnp number returns $expected_code");
+        $req = HTTP::Request->new('GET', $url);
+        $res = $ua->request($req);
+        is($res->code, 200, "fetch test lnp number");
+        my $got_number = JSON::from_json($res->decoded_content);
+        is_deeply($got_number,$number,"lnp number unchanged");
+        return undef;
+    }
+}
+
+sub _delete_lnp_number {
+
+    my ($number,$expected_code) = @_;
+    $expected_code //= 204;
+    my $url = $uri.'/api/lnpnumbers/'.$number->{id};
+    $req = HTTP::Request->new('DELETE', $url);
+    $res = $ua->request($req);
+    if ($expected_code eq '204') {
+        is($res->code, 204, "delete test lnp number");
+        $req = HTTP::Request->new('GET', $url);
+        $res = $ua->request($req);
+        is($res->code, 404, "test lnp number is not found");
+        return delete $number_map{$number->{id}};
+    } else {
+        is($res->code, $expected_code, "create test lnp number returns $expected_code");
+        $req = HTTP::Request->new('GET', $url);
+        $res = $ua->request($req);
+        is($res->code, 200, "test lnp number is still found");
+        return undef;
+    }
+
+}
+
+sub _create_lnp_provider {
+
+    my (%further_opts) = @_;
+    my $expected_code = delete $further_opts{expected_code} // 201;
+    $req = HTTP::Request->new('POST', $uri.'/api/lnpcarriers/');
+    $req->header('Content-Type' => 'application/json');
+    $req->content(JSON::to_json({
+        #skip_rewrite => JSON::false,
+        name => "test_lnp_carrier_".(scalar keys %carrier_map).'_'.$t,
+        prefix => 'test'.$t,
+        %further_opts,
+    }));
+    $res = $ua->request($req);
+    if ($expected_code eq '201') {
+        is($res->code, 201, "create test lnp carrier");
+        $req = HTTP::Request->new('GET', $uri.'/'.$res->header('Location'));
+        $res = $ua->request($req);
+        is($res->code, 200, "fetch test lnp carrier");
+        my $carrier = JSON::from_json($res->decoded_content);
+        $carrier_map{$carrier->{id}} = $carrier;
+        return $carrier;
+    } else {
+        is($res->code, $expected_code, "create test lnp carrier returns $expected_code");
+        return undef;
+    }
+
+}
+
+sub _delete_lnp_provider {
+
+    my ($carrier,$expected_code) = @_;
+    $expected_code //= 204;
+    my $url = $uri.'/api/lnpcarriers/'.$carrier->{id};
+    $req = HTTP::Request->new('DELETE', $url);
+    $res = $ua->request($req);
+    if ($expected_code eq '204') {
+        is($res->code, 204, "delete test lnp carrier");
+        $req = HTTP::Request->new('GET', $url);
+        $res = $ua->request($req);
+        is($res->code, 404, "test lnp carrier is not found");
+        return delete $carrier_map{$carrier->{id}};
+    } else {
+        is($res->code, $expected_code, "create test lnp carrier returns $expected_code");
+        $req = HTTP::Request->new('GET', $url);
+        $res = $ua->request($req);
+        is($res->code, 200, "test lnp carrier is still found");
+        return undef;
+    }
+
+}
+
+done_testing;