diff --git a/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriod/ProvidePersonsAssociated.php b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriod/ProvidePersonsAssociated.php
new file mode 100644
index 000000000..af1ae6e0f
--- /dev/null
+++ b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriod/ProvidePersonsAssociated.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\PersonBundle\Service\AccompanyingPeriod;
+
+use Chill\PersonBundle\Entity\AccompanyingPeriod;
+use Chill\PersonBundle\Entity\AccompanyingPeriodParticipation;
+use Chill\PersonBundle\Entity\Person;
+
+/**
+ * Provide persons associated with an accompanying period.
+ */
+class ProvidePersonsAssociated
+{
+    /**
+     * @return list<Person>
+     */
+    public function getPersonsAssociated(AccompanyingPeriod $period): array
+    {
+        return array_values(
+            $period->getCurrentParticipations()
+                ->map(fn (AccompanyingPeriodParticipation $participation) => $participation->getPerson())
+                ->toArray()
+        );
+    }
+}
diff --git a/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriod/ProvideThirdPartiesAssociated.php b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriod/ProvideThirdPartiesAssociated.php
new file mode 100644
index 000000000..5aa24bcda
--- /dev/null
+++ b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriod/ProvideThirdPartiesAssociated.php
@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\PersonBundle\Service\AccompanyingPeriod;
+
+use Chill\PersonBundle\Entity\AccompanyingPeriod;
+use Chill\PersonBundle\Entity\AccompanyingPeriod\Resource;
+use Chill\ThirdPartyBundle\Entity\ThirdParty;
+
+/**
+ * Provide third parties participating to an AccompanyingPeriod.
+ */
+class ProvideThirdPartiesAssociated
+{
+    /**
+     * @return list<ThirdParty>
+     */
+    public function getThirdPartiesAssociated(AccompanyingPeriod $period): array
+    {
+        $thirdParties = [];
+
+        foreach (
+            $period
+                ->getResources()->filter(fn (Resource $resource) => null !== $resource->getThirdParty())
+                ->map(fn (Resource $resource) => $resource->getThirdParty()) as $thirdParty) {
+            $thirdParties[] = $thirdParty;
+        }
+
+        if (null !== $requestor = $period->getRequestorThirdParty()) {
+            $thirdParties[] = $requestor;
+        }
+
+        return array_values(
+            // filter objects to remove duplicates
+            array_filter(
+                $thirdParties,
+                fn ($o, $k) => array_search($o, $thirdParties, true) === $k,
+                ARRAY_FILTER_USE_BOTH
+            )
+        );
+    }
+}
diff --git a/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriodWork/ProvidePersonsAssociated.php b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriodWork/ProvidePersonsAssociated.php
new file mode 100644
index 000000000..5fd885948
--- /dev/null
+++ b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriodWork/ProvidePersonsAssociated.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\PersonBundle\Service\AccompanyingPeriodWork;
+
+use Chill\PersonBundle\Entity\AccompanyingPeriod;
+use Chill\PersonBundle\Entity\Person;
+use Chill\PersonBundle\Service\AccompanyingPeriod\ProvidePersonsAssociated as ProvidePersonsAssociatedAccompanyingPeriod;
+
+/**
+ * Provide persons associated with an accompanying period work.
+ */
+class ProvidePersonsAssociated
+{
+    public function __construct(private readonly ProvidePersonsAssociatedAccompanyingPeriod $providePersonsAssociated) {}
+
+    /**
+     * @return list<Person>
+     */
+    public function getPersonsAssociated(AccompanyingPeriod\AccompanyingPeriodWork $work): array
+    {
+        return $this->providePersonsAssociated->getPersonsAssociated($work->getAccompanyingPeriod());
+    }
+}
diff --git a/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriodWork/ProvideThirdPartiesAssociated.php b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriodWork/ProvideThirdPartiesAssociated.php
new file mode 100644
index 000000000..2aa73935d
--- /dev/null
+++ b/src/Bundle/ChillPersonBundle/Service/AccompanyingPeriodWork/ProvideThirdPartiesAssociated.php
@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\PersonBundle\Service\AccompanyingPeriodWork;
+
+use Chill\PersonBundle\Entity\AccompanyingPeriod\AccompanyingPeriodWork;
+use Chill\PersonBundle\Service\AccompanyingPeriod\ProvideThirdPartiesAssociated as ProvideThirdPartiesAssociatedAccompanyingPeriod;
+use Chill\ThirdPartyBundle\Entity\ThirdParty;
+
+/**
+ * Provide third parties associated with an accompanying period work.
+ */
+class ProvideThirdPartiesAssociated
+{
+    public function __construct(private readonly ProvideThirdPartiesAssociatedAccompanyingPeriod $thirdPartiesAssociated) {}
+
+    /**
+     * @return list<ThirdParty>
+     */
+    public function getThirdPartiesAssociated(AccompanyingPeriodWork $accompanyingPeriodWork): array
+    {
+        $thirdParties = $this->thirdPartiesAssociated->getThirdPartiesAssociated($accompanyingPeriodWork->getAccompanyingPeriod());
+
+        if (null !== $tp = $accompanyingPeriodWork->getHandlingThierParty()) {
+            $thirdParties[] = $tp;
+        }
+
+        foreach ($accompanyingPeriodWork->getThirdParties() as $thirdParty) {
+            $thirdParties[] = $thirdParty;
+        }
+
+        return array_values(
+            // filter objects to remove duplicates
+            array_filter(
+                $thirdParties,
+                fn ($o, $k) => array_search($o, $thirdParties, true) === $k,
+                ARRAY_FILTER_USE_BOTH
+            )
+        );
+    }
+}
diff --git a/src/Bundle/ChillPersonBundle/Tests/Service/AccompanyingPeriod/ProvideThirdPartiesAssociatedTest.php b/src/Bundle/ChillPersonBundle/Tests/Service/AccompanyingPeriod/ProvideThirdPartiesAssociatedTest.php
new file mode 100644
index 000000000..ccc2a902e
--- /dev/null
+++ b/src/Bundle/ChillPersonBundle/Tests/Service/AccompanyingPeriod/ProvideThirdPartiesAssociatedTest.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\PersonBundle\Tests\Service\AccompanyingPeriod;
+
+use Chill\PersonBundle\Entity\AccompanyingPeriod;
+use Chill\PersonBundle\Entity\Person;
+use Chill\PersonBundle\Service\AccompanyingPeriod\ProvideThirdPartiesAssociated;
+use Chill\ThirdPartyBundle\Entity\ThirdParty;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @internal
+ *
+ * @coversNothing
+ */
+class ProvideThirdPartiesAssociatedTest extends TestCase
+{
+    public function testGetThirdPartiesAssociated()
+    {
+        $period = new AccompanyingPeriod();
+        $period->setRequestor($tp1 = new ThirdParty());
+        $period->addResource((new AccompanyingPeriod\Resource())->setResource($tp1));
+        $period->addResource((new AccompanyingPeriod\Resource())->setResource($tp2 = new ThirdParty()));
+        $period->addResource((new AccompanyingPeriod\Resource())->setResource($p1 = new Person()));
+
+        $provider = new ProvideThirdPartiesAssociated();
+
+        $thirdParties = $provider->getThirdPartiesAssociated($period);
+
+        self::assertCount(2, $thirdParties);
+        self::assertContains($tp1, $thirdParties);
+        self::assertContains($tp2, $thirdParties);
+        self::assertNotContains($p1, $thirdParties);
+        self::assertNotContains(null, $thirdParties);
+    }
+}
diff --git a/src/Bundle/ChillPersonBundle/Tests/Service/AccompanyingPeriodWork/ProvideThirdPartiesAssociatedTest.php b/src/Bundle/ChillPersonBundle/Tests/Service/AccompanyingPeriodWork/ProvideThirdPartiesAssociatedTest.php
new file mode 100644
index 000000000..5ce7b953e
--- /dev/null
+++ b/src/Bundle/ChillPersonBundle/Tests/Service/AccompanyingPeriodWork/ProvideThirdPartiesAssociatedTest.php
@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\PersonBundle\Tests\Service\AccompanyingPeriodWork;
+
+use Chill\PersonBundle\Entity\AccompanyingPeriod;
+use Chill\PersonBundle\Entity\Person;
+use Chill\PersonBundle\Service\AccompanyingPeriodWork\ProvideThirdPartiesAssociated;
+use Chill\ThirdPartyBundle\Entity\ThirdParty;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @internal
+ *
+ * @coversNothing
+ */
+class ProvideThirdPartiesAssociatedTest extends TestCase
+{
+    public function testGetThirdPartiesAssociated()
+    {
+        $period = new AccompanyingPeriod();
+        $period->setRequestor($tp1 = new ThirdParty());
+        $period->addResource((new AccompanyingPeriod\Resource())->setResource($tp1));
+        $period->addResource((new AccompanyingPeriod\Resource())->setResource($tp2 = new ThirdParty()));
+        $period->addResource((new AccompanyingPeriod\Resource())->setResource($p1 = new Person()));
+        $period->addWork($work = new AccompanyingPeriod\AccompanyingPeriodWork());
+        $work->addThirdParty($tp3 = new ThirdParty());
+        $work->addThirdParty($tp1);
+        $work->setHandlingThierParty($tp4 = new ThirdParty());
+
+        $providerAccPeriod = new \Chill\PersonBundle\Service\AccompanyingPeriod\ProvideThirdPartiesAssociated();
+        $provider = new ProvideThirdPartiesAssociated($providerAccPeriod);
+
+
+        $thirdParties = $provider->getThirdPartiesAssociated($work);
+
+        self::assertContains($tp1, $thirdParties);
+        self::assertContains($tp2, $thirdParties);
+        self::assertContains($tp3, $thirdParties);
+        self::assertContains($tp4, $thirdParties);
+        self::assertNotContains($p1, $thirdParties);
+        self::assertCount(4, $thirdParties);
+    }
+}