diff --git a/admin/marctagstructure.pl b/admin/marctagstructure.pl
index 96eeedfef2..1e89615e0d 100755
--- a/admin/marctagstructure.pl
+++ b/admin/marctagstructure.pl
@@ -28,6 +28,7 @@ use C4::Context;
 use Koha::Caches;
 use Koha::AuthorisedValues;
 use Koha::BiblioFrameworks;
+use Koha::Database;
 
 # retrieve parameters
 my $input = CGI->new;
@@ -120,6 +121,7 @@ if ($op eq 'add_form') {
 	my $authorised_value = $input->param('authorised_value');
     my $ind1_defaultvalue = $input->param('ind1_defaultvalue');
     my $ind2_defaultvalue = $input->param('ind2_defaultvalue');
+    my $error;
     if ($input->param('modif')) {
         $sth = $dbh->prepare(
         "UPDATE marc_tag_structure SET liblibrarian=? ,libopac=? ,repeatable=? ,mandatory=? ,important=? ,authorised_value=?, ind1_defaultvalue=?, ind2_defaultvalue=? WHERE frameworkcode=? AND tagfield=?"
@@ -136,26 +138,40 @@ if ($op eq 'add_form') {
                         $tagfield
         );
     } else {
-        $sth = $dbh->prepare(
-        "INSERT INTO marc_tag_structure (tagfield,liblibrarian,libopac,repeatable,mandatory,important,authorised_value,ind1_defaultvalue,ind2_defaultvalue,frameworkcode) values (?,?,?,?,?,?,?,?,?,?)"
-        );
-        $sth->execute($tagfield,
-                      $liblibrarian,
-                      $libopac,
-                      $repeatable,
-                      $mandatory,
-                      $important,
-                      $authorised_value,
-                      $ind1_defaultvalue,
-                      $ind2_defaultvalue,
-                      $frameworkcode
-        );
+        my $schema = Koha::Database->new()->schema();
+        my $rs     = $schema->resultset('MarcTagStructure');
+        my $field  = $rs->find( { tagfield => $tagfield, frameworkcode => $frameworkcode } );
+        if ( !$field ) {
+            $sth = $dbh->prepare(
+                "INSERT INTO marc_tag_structure (tagfield,liblibrarian,libopac,repeatable,mandatory,important,authorised_value,ind1_defaultvalue,ind2_defaultvalue,frameworkcode) values (?,?,?,?,?,?,?,?,?,?)"
+            );
+            $sth->execute(
+                $tagfield,
+                $liblibrarian,
+                $libopac,
+                $repeatable,
+                $mandatory,
+                $important,
+                $authorised_value,
+                $ind1_defaultvalue,
+                $ind2_defaultvalue,
+                $frameworkcode
+            );
+        } else {
+            $error = 'duplicate_tagfield';
+        }
     }
-    $cache->clear_from_cache("MarcStructure-0-$frameworkcode");
-    $cache->clear_from_cache("MarcStructure-1-$frameworkcode");
-    $cache->clear_from_cache("MarcSubfieldStructure-$frameworkcode");
-    $cache->clear_from_cache("MarcCodedFields-$frameworkcode");
-    print $input->redirect("/cgi-bin/koha/admin/marctagstructure.pl?searchfield=$tagfield&frameworkcode=$frameworkcode");
+    if ( !$error ) {
+        $cache->clear_from_cache("MarcStructure-0-$frameworkcode");
+        $cache->clear_from_cache("MarcStructure-1-$frameworkcode");
+        $cache->clear_from_cache("MarcSubfieldStructure-$frameworkcode");
+        $cache->clear_from_cache("MarcCodedFields-$frameworkcode");
+    }
+    my $redirect_url = "/cgi-bin/koha/admin/marctagstructure.pl?searchfield=$tagfield&frameworkcode=$frameworkcode";
+    if ($error) {
+        $redirect_url .= "&error=$error";
+    }
+    print $input->redirect($redirect_url);
     exit;
 													# END $OP eq ADD_VALIDATE
 ################## DELETE_CONFIRM ##################################
@@ -200,6 +216,12 @@ if ($op eq 'add_form') {
 
 ################## DEFAULT ##################################
 } else { # DEFAULT
+    my $error_code = $input->param('error');
+    if ($error_code){
+        if ($error_code eq 'duplicate_tagfield'){
+            $template->param('blocking_error' => $error_code);
+        }
+    }
 	# here, $op can be unset or set to "cud-framework_create_confirm".
     if ($searchfield ne '') {
         $template->param(searchfield => $searchfield);
diff --git a/koha-tmpl/intranet-tmpl/prog/en/includes/blocking_errors.inc b/koha-tmpl/intranet-tmpl/prog/en/includes/blocking_errors.inc
index a4fd22249e..20376d1ed8 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/includes/blocking_errors.inc
+++ b/koha-tmpl/intranet-tmpl/prog/en/includes/blocking_errors.inc
@@ -22,9 +22,11 @@
     [% CASE 'budget_is_locked' %]
         <div class="dialog message">The budget is locked, fund creation is not possible.</div>
     [% CASE 'missing_es_modules' %]
-        <div class="dialog message">Necessary Elasticsearch packages are not installed on your server. Please contact your server admin if you wish to configure Elasticsearch</div>
+        <div class="dialog message">Necessary Elasticsearch packages are not installed on your server. Please contact your server admin if you wish to configure Elasticsearch.</div>
     [% CASE 'insufficient_permission' %]
         <div class="dialog message">You do not have sufficient permission to continue.</div>
+    [% CASE 'duplicate_tagfield' %]
+        <div class="dialog message">MARC field not added to MARC bibliographic framework. MARC tag already exists in framework.</div>
     [% CASE %]
         <div class="dialog alert">[% blocking_error | html %]</div>
     [% END %]