diff --git a/Koha/Biblio/Metadata/Extractor/MARC/MARC21.pm b/Koha/Biblio/Metadata/Extractor/MARC/MARC21.pm
index d4a1b6ea8e..42cd8ec523 100644
--- a/Koha/Biblio/Metadata/Extractor/MARC/MARC21.pm
+++ b/Koha/Biblio/Metadata/Extractor/MARC/MARC21.pm
@@ -96,6 +96,60 @@ sub get_normalized_oclc {
     }
 }
 
+=head2 check_fixed_length
+
+    my $info = $extractor->check_fixed_length;
+
+Returns a hash containing passed and failed fixed-length control fields.
+
+=cut
+
+sub check_fixed_length {
+    my $self   = shift;
+    my $len_ok = {
+        '005' => 16,
+        '006' => 18,
+        '007' => {
+            a => 8,
+            c => [ 6, 14 ],
+            d => 6,
+            f => 10,
+            g => 9,
+            h => 13,
+            k => 6,
+            m => [ 8, 23 ],
+            o => 2,
+            q => 2,
+            r => 11,
+            s => 14,
+            t => 2,
+            v => 9,
+            z => 2,
+        },
+        '008' => 40,
+    };
+    my $record = $self->metadata;
+    my $result = { passed => [], failed => [] };
+    foreach my $field ( $record->field( '005', '006', '007', '008' ) ) {
+        my ( $length, $pass );
+        if ( $field->tag ne '007' ) {
+            $length = $len_ok->{ $field->tag };
+            $pass   = length( $field->data ) eq $length;
+        } else {
+            my $pos_0 = substr( $field->data, 0, 1 );
+            $length = $len_ok->{ $field->tag }->{$pos_0};
+            if ( ref($length) eq 'ARRAY' ) {
+                $pass = grep { $_ eq length( $field->data ) } @$length;
+            } else {
+                $pass = length( $field->data ) eq $length;
+            }
+        }
+        push @{ $result->{passed} }, $field->tag if $pass;
+        push @{ $result->{failed} }, $field->tag unless $pass;
+    }
+    return $result;
+}
+
 =head1 AUTHOR
 
 Tomas Cohen Arazi, E<lt>tomascohen@theke.ioE<gt>
diff --git a/cataloguing/addbiblio.pl b/cataloguing/addbiblio.pl
index 46f28d19df..d7ec674e6e 100755
--- a/cataloguing/addbiblio.pl
+++ b/cataloguing/addbiblio.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl 
+#!/usr/bin/perl
 
 # Copyright 2000-2002 Katipo Communications
 # Copyright 2004-2010 BibLibre
@@ -52,7 +52,7 @@ use Koha::Biblios;
 use Koha::ItemTypes;
 use Koha::Libraries;
 
-use Koha::BiblioFrameworks;
+use Koha::Biblio::Metadata::Extractor::MARC::MARC21;
 use Koha::Patrons;
 use Koha::UI::Form::Builder::Biblio;
 
@@ -834,6 +834,13 @@ if ( $op eq "cud-addbiblio" ) {
     #----------------------------------------------------------------------------
     # If we're in a duplication case, we have to set to "" the biblionumber
     # as we'll save the biblio as a new one.
+
+    if ( C4::Context->preference('marcflavour') eq 'MARC21' ) {
+        my $fixed_length_info =
+            Koha::Biblio::Metadata::Extractor::MARC::MARC21->new( { biblio => $biblio } )->check_fixed_length;
+        $template->param( marc21_fixlen => $fixed_length_info ) if @{ $fixed_length_info->{failed} };
+    }
+
     $template->param(
         biblionumberdata => $biblionumber,
         op               => $op,
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/cataloguing/addbiblio.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/cataloguing/addbiblio.tt
index 7d75f7970c..59ef6c8969 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/cataloguing/addbiblio.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/cataloguing/addbiblio.tt
@@ -805,6 +805,10 @@
         </div>
     [% END %]
 
+    [% IF marc21_fixlen %]
+        <div class="alert alert-warning"><h1>WARNING</h1><p>The following fixed-length control field(s) have an invalid length: [% marc21_fixlen.failed.join(',') | html %]. Please fix.</p></div>
+    [% END %]
+
     [% IF ( Koha.Preference('EnableAdvancedCatalogingEditor') && CAN_user_editcatalogue_advanced_editor ) %]
         <div id="toggle-editor">
             <label for="toggle-editor">Advanced editor: </label>
diff --git a/t/db_dependent/Koha/Biblio/Metadata/Extractor/MARC/MARC21.t b/t/db_dependent/Koha/Biblio/Metadata/Extractor/MARC/MARC21.t
index c58aac39b8..6797cb5ed5 100755
--- a/t/db_dependent/Koha/Biblio/Metadata/Extractor/MARC/MARC21.t
+++ b/t/db_dependent/Koha/Biblio/Metadata/Extractor/MARC/MARC21.t
@@ -20,13 +20,15 @@
 use Modern::Perl;
 
 use Test::NoWarnings;
-use Test::More tests => 4;
+use Test::More tests => 5;
 use Test::Exception;
 
 use t::lib::TestBuilder;
 use t::lib::Mocks;
 
+use C4::Biblio qw(ModBiblio);
 use Koha::Biblio::Metadata::Extractor;
+use Koha::Biblio::Metadata::Extractor::MARC::MARC21;
 
 my $schema  = Koha::Database->schema;
 my $builder = t::lib::TestBuilder->new;
@@ -87,3 +89,39 @@ subtest 'get_normalized_oclc() tests' => sub {
     is( $extractor->get_normalized_oclc, "" );
 
 };
+
+subtest 'check_fixed_length' => sub {
+
+    plan tests => 6;
+    $schema->storage->txn_begin;
+
+    my $record = MARC::Record->new;
+    $record->append_fields(
+        MARC::Field->new( '005', '0123456789012345' ),
+    );
+    my $biblio = $builder->build_sample_biblio;
+    ModBiblio( $record, $biblio->biblionumber );
+
+    my $extractor;
+    $extractor = Koha::Biblio::Metadata::Extractor::MARC::MARC21->new( { biblio => $biblio } );
+    my $result = $extractor->check_fixed_length;
+    is( $result->{passed}->[0],        '005', 'Check first passed field' );
+    is( scalar @{ $result->{failed} }, 0,     'Check failed count' );
+
+    $record->append_fields(
+        MARC::Field->new( '006', '01234567890123456789' ),      # too long
+        MARC::Field->new( '007', 'a1234567' ),
+        MARC::Field->new( '007', 'm12345678' ),                 # should be 8 or 23
+        MARC::Field->new( '007', 'm1234567890123456789012' ),
+    );
+
+    # Passing latest record changes via metadata now
+    $extractor = Koha::Biblio::Metadata::Extractor::MARC::MARC21->new( { metadata => $record } );
+    $result    = $extractor->check_fixed_length;
+    is( $result->{passed}->[1], '007', 'Check second passed field' );
+    is( $result->{passed}->[2], '007', 'Check third passed field' );
+    is( $result->{failed}->[0], '006', 'Check first failed field' );
+    is( $result->{failed}->[1], '007', 'Check second failed field' );
+
+    $schema->storage->txn_rollback;
+};