diff --git a/.changes/unreleased/Fixed-20251230-125728.yaml b/.changes/unreleased/Fixed-20251230-125728.yaml
new file mode 100644
index 000000000..2ee7b761a
--- /dev/null
+++ b/.changes/unreleased/Fixed-20251230-125728.yaml
@@ -0,0 +1,6 @@
+kind: Fixed
+body: Fix export group by center for persons without a center in CenterAggregator.php
+time: 2025-12-30T12:57:28.773521385+01:00
+custom:
+    Issue: "477"
+    SchemaChange: No schema change
diff --git a/src/Bundle/ChillPersonBundle/Export/Aggregator/PersonAggregators/CenterAggregator.php b/src/Bundle/ChillPersonBundle/Export/Aggregator/PersonAggregators/CenterAggregator.php
index 6f4082d46..bf9901207 100644
--- a/src/Bundle/ChillPersonBundle/Export/Aggregator/PersonAggregators/CenterAggregator.php
+++ b/src/Bundle/ChillPersonBundle/Export/Aggregator/PersonAggregators/CenterAggregator.php
@@ -19,6 +19,7 @@ use Chill\MainBundle\Service\RollingDate\RollingDateConverterInterface;
 use Chill\PersonBundle\Export\Declarations;
 use Doctrine\ORM\QueryBuilder;
 use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 final readonly class CenterAggregator implements AggregatorInterface
 {
@@ -27,6 +28,7 @@ final readonly class CenterAggregator implements AggregatorInterface
     public function __construct(
         private CenterRepositoryInterface $centerRepository,
         private RollingDateConverterInterface $rollingDateConverter,
+        private TranslatorInterface $translator,
     ) {}
 
     public function buildForm(FormBuilderInterface $builder): void
@@ -62,7 +64,7 @@ final readonly class CenterAggregator implements AggregatorInterface
     {
         return function (int|string|null $value) {
             if (null === $value || '' === $value) {
-                return '';
+                return $this->translator->trans('person.export.aggregator.by_center.no_center');
             }
 
             if ('_header' === $value) {
@@ -94,15 +96,18 @@ final readonly class CenterAggregator implements AggregatorInterface
         $atDate = 'pers_center_agg_at_date';
 
         $qb->leftJoin('person.centerHistory', $alias);
-        $qb
-            ->andWhere(
-                $qb->expr()->lte($alias.'.startDate', ':'.$atDate),
-            )->andWhere(
-                $qb->expr()->orX(
-                    $qb->expr()->isNull($alias.'.endDate'),
-                    $qb->expr()->gt($alias.'.endDate', ':'.$atDate)
+        $qb->andWhere(
+            $qb->expr()->orX(
+                $qb->expr()->isNull($alias.'.id'),
+                $qb->expr()->andX(
+                    $qb->expr()->lte($alias.'.startDate', ':'.$atDate),
+                    $qb->expr()->orX(
+                        $qb->expr()->isNull($alias.'.endDate'),
+                        $qb->expr()->gt($alias.'.endDate', ':'.$atDate)
+                    )
                 )
-            );
+            )
+        );
         $qb->setParameter($atDate, $this->rollingDateConverter->convert($data['at_date']));
 
         $qb->addSelect("IDENTITY({$alias}.center) AS ".self::COLUMN_NAME);
diff --git a/src/Bundle/ChillPersonBundle/translations/messages.fr.yml b/src/Bundle/ChillPersonBundle/translations/messages.fr.yml
index 88b12f7bd..b62908dc0 100644
--- a/src/Bundle/ChillPersonBundle/translations/messages.fr.yml
+++ b/src/Bundle/ChillPersonBundle/translations/messages.fr.yml
@@ -103,6 +103,11 @@ Employment status: Situation professionelle
 Administrative status: Situation administrative
 
 person:
+    # trans key according to new conventions
+    export:
+        aggregator:
+            by_center:
+                no_center: Sans territoire
     Identifiers: Identifiants