diff --git a/t/db_dependent/Circulation.t b/t/db_dependent/Circulation.t
index e663e3e6f3..ade7d89715 100755
--- a/t/db_dependent/Circulation.t
+++ b/t/db_dependent/Circulation.t
@@ -19,7 +19,7 @@ use Modern::Perl;
 use utf8;
 
 use Test::NoWarnings;
-use Test::More tests => 82;
+use Test::More tests => 83;
 use Test::Exception;
 use Test::MockModule;
 use Test::Deep qw( cmp_deeply );
@@ -8005,6 +8005,25 @@ subtest 'Bug 9762: AddRenewal override JSON logging' => sub {
     is_deeply( $log_data->{forced},        ['TOO_MUCH'],                      'Forced overrides logged correctly' );
 };
 
+subtest 'Bug 40866: CanBookBeIssued returns correct number of values' => sub {
+    plan tests => 2;
+
+    my $library = $builder->build_object( { class => 'Koha::Libraries' } );
+    my $patron =
+        $builder->build_object( { class => 'Koha::Patrons', value => { branchcode => $library->branchcode } } );
+    my $item = $builder->build_sample_item( { library => $library->branchcode } );
+
+    t::lib::Mocks::mock_userenv( { patron => $patron, branchcode => $library->branchcode } );
+
+    # CanBookBeIssued should return exactly 4 values after Bug 40866 cleanup
+    # (issuingimpossible, needsconfirmation, alerts, messages)
+    # The 5th return value (@message_log) from the original Bug 9762 implementation was removed
+    my @result = C4::Circulation::CanBookBeIssued( $patron, $item->barcode );
+
+    is( scalar @result, 4, 'CanBookBeIssued returns exactly 4 values' );
+    ok( ref( $result[0] ) eq 'HASH', 'First return value is issuingimpossible hashref' );
+};
+
 $schema->storage->txn_rollback;
 C4::Context->clear_syspref_cache();
 $branches = Koha::Libraries->search();
diff --git a/t/db_dependent/Reserves.t b/t/db_dependent/Reserves.t
index 22778875a2..33a99d714e 100755
--- a/t/db_dependent/Reserves.t
+++ b/t/db_dependent/Reserves.t
@@ -17,7 +17,7 @@
 
 use Modern::Perl;
 
-use Test::More tests => 70;
+use Test::More tests => 71;
 use Test::NoWarnings;
 use Test::MockModule;
 use Test::Warn;
@@ -25,6 +25,7 @@ use Test::Warn;
 use t::lib::Mocks;
 use t::lib::TestBuilder;
 
+use JSON qw( from_json );
 use MARC::Record;
 use DateTime::Duration;
 
@@ -2004,3 +2005,92 @@ subtest 'CheckReserves() item type tests' => sub {
 
     $schema->storage->txn_rollback;
 };
+
+subtest 'Bug 40866: AddReserve override JSON logging' => sub {
+    plan tests => 8;
+
+    $schema->storage->txn_begin;
+
+    my $library = $builder->build_object( { class => 'Koha::Libraries' } );
+    my $patron  = $builder->build_object(
+        {
+            class => 'Koha::Patrons',
+            value => { branchcode => $library->branchcode }
+        }
+    );
+    my $biblio = $builder->build_sample_biblio();
+    my $item   = $builder->build_sample_item(
+        {
+            library      => $library->branchcode,
+            biblionumber => $biblio->biblionumber
+        }
+    );
+
+    t::lib::Mocks::mock_userenv( { patron => $patron, branchcode => $library->branchcode } );
+    t::lib::Mocks::mock_preference( 'HoldsLog', 1 );
+
+    # Clear any existing logs
+    Koha::ActionLogs->search( { module => 'HOLDS', action => 'CREATE' } )->delete;
+
+    # Test 1: Normal hold without overrides - should log hold ID only
+    my $hold_id = C4::Reserves::AddReserve(
+        {
+            branchcode     => $library->branchcode,
+            borrowernumber => $patron->borrowernumber,
+            biblionumber   => $biblio->biblionumber,
+            priority       => 1,
+        }
+    );
+    ok( $hold_id, 'Hold created successfully' );
+
+    my $logs = Koha::ActionLogs->search(
+        {
+            module => 'HOLDS',
+            action => 'CREATE',
+            object => $hold_id
+        },
+        { order_by => { -desc => 'timestamp' } }
+    );
+    is( $logs->count, 1, 'One log entry created for normal hold' );
+    my $log = $logs->next;
+    is( $log->info, $hold_id, 'Normal hold logs hold ID only' );
+
+    # Cancel the hold for next test
+    my $hold = Koha::Holds->find($hold_id);
+    $hold->cancel;
+
+    # Test 2: Hold with override confirmation - should log JSON with confirmations
+    my $hold_id2 = C4::Reserves::AddReserve(
+        {
+            branchcode     => $library->branchcode,
+            borrowernumber => $patron->borrowernumber,
+            biblionumber   => $biblio->biblionumber,
+            priority       => 1,
+            confirmations  => ['HOLD_POLICY_OVERRIDE'],
+            forced         => []
+        }
+    );
+    ok( $hold_id2, 'Hold with override created successfully' );
+
+    $logs = Koha::ActionLogs->search(
+        {
+            module => 'HOLDS',
+            action => 'CREATE',
+            object => $hold_id2
+        },
+        { order_by => { -desc => 'timestamp' } }
+    );
+    is( $logs->count, 1, 'One log entry created for override hold' );
+    $log = $logs->next;
+
+    my $log_data = eval { from_json( $log->info ) };
+    ok( !$@,                               'Log info is valid JSON' );
+    ok( exists $log_data->{confirmations}, 'JSON contains confirmations array' );
+    is_deeply(
+        $log_data->{confirmations},
+        ['HOLD_POLICY_OVERRIDE'],
+        'Confirmations logged correctly'
+    );
+
+    $schema->storage->txn_rollback;
+};
diff --git a/t/db_dependent/api/v1/holds.t b/t/db_dependent/api/v1/holds.t
index 333a20726e..a0e15daeb7 100755
--- a/t/db_dependent/api/v1/holds.t
+++ b/t/db_dependent/api/v1/holds.t
@@ -17,7 +17,7 @@
 
 use Modern::Perl;
 
-use Test::More tests => 18;
+use Test::More tests => 19;
 use Test::NoWarnings;
 use Test::MockModule;
 use Test::Mojo;
@@ -25,6 +25,7 @@ use t::lib::TestBuilder;
 use t::lib::Mocks;
 
 use DateTime;
+use JSON       qw( from_json );
 use Mojo::JSON qw(encode_json);
 
 use C4::Context;
@@ -32,6 +33,7 @@ use Koha::Patrons;
 use C4::Reserves qw( AddReserve CanItemBeReserved CanBookBeReserved );
 use C4::Items;
 
+use Koha::ActionLogs;
 use Koha::Database;
 use Koha::DateUtils qw( dt_from_string output_pref );
 use Koha::Biblios;
@@ -1885,3 +1887,71 @@ subtest 'PUT /holds/{hold_id}/lowest_priority tests' => sub {
 
     $schema->storage->txn_rollback;
 };
+
+subtest 'Bug 40866: API hold creation with override logs confirmations' => sub {
+    plan tests => 6;
+
+    $schema->storage->txn_begin;
+
+    my $librarian = $builder->build_object(
+        {
+            class => 'Koha::Patrons',
+            value => { flags => 1 }
+        }
+    );
+    my $password = 'thePassword123';
+    $librarian->set_password( { password => $password, skip_validation => 1 } );
+    my $userid = $librarian->userid;
+
+    my $patron = $builder->build_object(
+        {
+            class => 'Koha::Patrons',
+            value => { flags => 0 }
+        }
+    );
+
+    my $library = $builder->build_object( { class => 'Koha::Libraries' } );
+    my $biblio  = $builder->build_sample_biblio;
+
+    t::lib::Mocks::mock_preference( 'AllowHoldPolicyOverride', 1 );
+    t::lib::Mocks::mock_preference( 'HoldsLog',                1 );
+
+    # Clear any existing logs
+    Koha::ActionLogs->search( { module => 'HOLDS', action => 'CREATE' } )->delete;
+
+    my $post_data = {
+        patron_id         => $patron->id,
+        biblio_id         => $biblio->id,
+        pickup_library_id => $library->branchcode,
+    };
+
+    # Create hold with override
+    my $hold_id =
+        $t->post_ok( "//$userid:$password@/api/v1/holds" => { 'x-koha-override' => 'any' } => json => $post_data )
+        ->status_is(201)->tx->res->json->{hold_id};
+
+    ok( $hold_id, 'Hold created via API with override' );
+
+    # Verify the hold was logged with override information
+    my $logs = Koha::ActionLogs->search(
+        {
+            module => 'HOLDS',
+            action => 'CREATE',
+            object => $hold_id
+        },
+        { order_by => { -desc => 'timestamp' } }
+    );
+
+    is( $logs->count, 1, 'One log entry created for API hold with override' );
+
+    my $log      = $logs->next;
+    my $log_data = eval { from_json( $log->info ) };
+    ok( !$@, 'Log info is valid JSON' );
+    is_deeply(
+        $log_data->{confirmations},
+        ['HOLD_POLICY_OVERRIDE'],
+        'HOLD_POLICY_OVERRIDE logged in confirmations array'
+    );
+
+    $schema->storage->txn_rollback;
+};