diff --git a/src/Controller/Contracts/MaxHoursController.php b/src/Controller/Contracts/MaxHoursController.php
new file mode 100644
index 00000000..80860760
--- /dev/null
+++ b/src/Controller/Contracts/MaxHoursController.php
@@ -0,0 +1,72 @@
+<?php
+
+// This file is part of Bileto.
+// Copyright 2022-2023 Probesys
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace App\Controller\Contracts;
+
+use App\Controller\BaseController;
+use App\Entity\Contract;
+use App\Repository\ContractRepository;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\Routing\Annotation\Route;
+use Symfony\Contracts\Translation\TranslatorInterface;
+
+class MaxHoursController extends BaseController
+{
+    #[Route('/contracts/{uid}/max-hours/edit', name: 'edit contract max hours', methods: ['GET', 'HEAD'])]
+    public function edit(
+        Contract $contract,
+        Request $request,
+    ): Response {
+        $organization = $contract->getOrganization();
+
+        $this->denyAccessUnlessGranted('orga:manage:contracts', $organization);
+
+        return $this->render('contracts/max_hours/edit.html.twig', [
+            'organization' => $organization,
+            'contract' => $contract,
+            'additionalHours' => 0,
+        ]);
+    }
+
+    #[Route('/contracts/{uid}/max-hours/edit', name: 'update contract max hours', methods: ['POST'])]
+    public function update(
+        Contract $contract,
+        Request $request,
+        ContractRepository $contractRepository,
+        TranslatorInterface $translator,
+    ): Response {
+        $organization = $contract->getOrganization();
+
+        $this->denyAccessUnlessGranted('orga:manage:contracts', $organization);
+
+        $additionalHours = $request->request->getInt('additionalHours');
+        $csrfToken = $request->request->getString('_csrf_token');
+
+        if ($additionalHours < 0) {
+            $additionalHours = 0;
+        }
+
+        if (!$this->isCsrfTokenValid('update contract max hours', $csrfToken)) {
+            return $this->renderBadRequest('contracts/max_hours/edit.html.twig', [
+                'organization' => $organization,
+                'contract' => $contract,
+                'additionalHours' => $additionalHours,
+                'error' => $translator->trans('csrf.invalid', [], 'errors'),
+            ]);
+        }
+
+        $maxHours = $contract->getMaxHours() + $additionalHours;
+        $contract->setMaxHours($maxHours);
+
+        $contractRepository->save($contract, true);
+
+        return $this->redirectToRoute('organization contract', [
+            'uid' => $organization->getUid(),
+            'contract_uid' => $contract->getUid(),
+        ]);
+    }
+}
diff --git a/templates/contracts/max_hours/edit.html.twig b/templates/contracts/max_hours/edit.html.twig
new file mode 100644
index 00000000..18dc1255
--- /dev/null
+++ b/templates/contracts/max_hours/edit.html.twig
@@ -0,0 +1,46 @@
+{#
+ # This file is part of Bileto.
+ # Copyright 2022-2023 Probesys
+ # SPDX-License-Identifier: AGPL-3.0-or-later
+ #}
+
+{% extends 'modal.html.twig' %}
+
+{% block title %}{{ 'contracts.max_hours.edit.title' | trans }}{% endblock %}
+
+{% block body %}
+    <form
+        action="{{ path('update contract max hours', {'uid': contract.uid}) }}"
+        method="post"
+        class="wrapper wrapper--small wrapper--center flow"
+    >
+        <input type="hidden" name="_csrf_token" value="{{ csrf_token('update contract max hours') }}">
+
+        {% if error %}
+            {{ include('alerts/_error.html.twig', { message: error }, with_context = false) }}
+        {% endif %}
+
+        <div class="flow flow--small">
+            <label for="additional-hours">
+                {{ 'contracts.max_hours.edit.additional_hours' | trans }}
+            </label>
+
+            <input
+                type="number"
+                id="additional-hours"
+                name="additionalHours"
+                value="{{ additionalHours }}"
+                min="0"
+                step="1"
+                required
+                class="input--size3"
+            />
+        </div>
+
+        <div class="form__actions">
+            <button class="button--primary" type="submit">
+                {{ 'forms.save_changes' | trans }}
+            </button>
+        </div>
+    </form>
+{% endblock %}
diff --git a/templates/organizations/contracts/show.html.twig b/templates/organizations/contracts/show.html.twig
index 5b95349b..441893b6 100644
--- a/templates/organizations/contracts/show.html.twig
+++ b/templates/organizations/contracts/show.html.twig
@@ -49,9 +49,20 @@
             {% endif %}
 
             <div class="flow flow--small">
-                <span class="text--small" id="contract-hours-consumed">
-                    {{ 'contracts.hours_consumed' | trans({ 'hours': contract.consumedMinutes | formatMinutes, 'maxHours': contract.maxHours }) | raw }}
-                </span>
+                <div class="row row--center row--always flow text--small">
+                    <div class="row__item--extend" id="contract-hours-consumed">
+                        {{ 'contracts.hours_consumed' | trans({ 'hours': contract.consumedMinutes | formatMinutes, 'maxHours': contract.maxHours }) | raw }}
+                    </div>
+
+                    <button
+                        class="button--discreet"
+                        data-controller="modal-opener"
+                        data-action="modal-opener#fetch"
+                        data-modal-opener-href-value="{{ path('edit contract max hours', { uid: contract.uid }) }}"
+                    >
+                        {{ 'contracts.show.extend' | trans }}
+                    </button>
+                </div>
 
                 <progress value="{{ contract.consumedHours }}" max="{{ contract.maxHours }}" aria-labelledby="contract-hours-consumed">
                 </progress>
diff --git a/tests/Controller/Contracts/MaxHoursControllerTest.php b/tests/Controller/Contracts/MaxHoursControllerTest.php
new file mode 100644
index 00000000..ca8c4a6e
--- /dev/null
+++ b/tests/Controller/Contracts/MaxHoursControllerTest.php
@@ -0,0 +1,133 @@
+<?php
+
+// This file is part of Bileto.
+// Copyright 2022-2023 Probesys
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace App\Tests\Controller\Tickets;
+
+use App\Tests\AuthorizationHelper;
+use App\Tests\Factory\ContractFactory;
+use App\Tests\Factory\UserFactory;
+use App\Tests\SessionHelper;
+use App\Utils;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+use Symfony\Component\Security\Core\Exception\AccessDeniedException;
+use Zenstruck\Foundry\Test\Factories;
+use Zenstruck\Foundry\Test\ResetDatabase;
+
+class MaxHoursControllerTest extends WebTestCase
+{
+    use AuthorizationHelper;
+    use Factories;
+    use ResetDatabase;
+    use SessionHelper;
+
+    public function testGetEditRendersCorrectly(): void
+    {
+        $client = static::createClient();
+        $user = UserFactory::createOne();
+        $client->loginUser($user->object());
+        $this->grantOrga($user->object(), ['orga:manage:contracts']);
+        $contract = ContractFactory::createOne();
+
+        $client->request('GET', "/contracts/{$contract->getUid()}/max-hours/edit");
+
+        $this->assertResponseIsSuccessful();
+        $this->assertSelectorTextContains('h1', 'Extend the number of hours of the contract');
+    }
+
+    public function testGetEditFailsIfAccessIsForbidden(): void
+    {
+        $this->expectException(AccessDeniedException::class);
+
+        $client = static::createClient();
+        $user = UserFactory::createOne();
+        $client->loginUser($user->object());
+        $contract = ContractFactory::createOne();
+
+        $client->catchExceptions(false);
+        $client->request('GET', "/contracts/{$contract->getUid()}/max-hours/edit");
+    }
+
+    public function testPostUpdateSavesTheMaxHours(): void
+    {
+        $client = static::createClient();
+        $user = UserFactory::createOne();
+        $client->loginUser($user->object());
+        $this->grantOrga($user->object(), ['orga:manage:contracts']);
+        $contract = ContractFactory::createOne([
+            'maxHours' => 10,
+        ]);
+
+        $client->request('POST', "/contracts/{$contract->getUid()}/max-hours/edit", [
+            '_csrf_token' => $this->generateCsrfToken($client, 'update contract max hours'),
+            'additionalHours' => 5,
+        ]);
+
+        $organization = $contract->getOrganization();
+        $this->assertResponseRedirects("/organizations/{$organization->getUid()}/contracts/{$contract->getUid()}", 302);
+        $contract->refresh();
+        $this->assertSame(15, $contract->getMaxHours());
+    }
+
+    public function testPostUpdateDoesNotAcceptNegativeAdditionalHours(): void
+    {
+        $client = static::createClient();
+        $user = UserFactory::createOne();
+        $client->loginUser($user->object());
+        $this->grantOrga($user->object(), ['orga:manage:contracts']);
+        $contract = ContractFactory::createOne([
+            'maxHours' => 10,
+        ]);
+
+        $client->request('POST', "/contracts/{$contract->getUid()}/max-hours/edit", [
+            '_csrf_token' => $this->generateCsrfToken($client, 'update contract max hours'),
+            'additionalHours' => -5,
+        ]);
+
+        $organization = $contract->getOrganization();
+        $this->assertResponseRedirects("/organizations/{$organization->getUid()}/contracts/{$contract->getUid()}", 302);
+        $contract->refresh();
+        $this->assertSame(10, $contract->getMaxHours());
+    }
+
+    public function testPostUpdateFailsIfCsrfTokenIsInvalid(): void
+    {
+        $client = static::createClient();
+        $user = UserFactory::createOne();
+        $client->loginUser($user->object());
+        $this->grantOrga($user->object(), ['orga:manage:contracts']);
+        $contract = ContractFactory::createOne([
+            'maxHours' => 10,
+        ]);
+
+        $client->request('POST', "/contracts/{$contract->getUid()}/max-hours/edit", [
+            '_csrf_token' => 'not the token',
+            'additionalHours' => 5,
+        ]);
+
+        $organization = $contract->getOrganization();
+        $this->assertSelectorTextContains('[data-test="alert-error"]', 'The security token is invalid');
+        $contract->refresh();
+        $this->assertSame(10, $contract->getMaxHours());
+    }
+
+    public function testPostUpdateFailsIfAccessIsForbidden(): void
+    {
+        $this->expectException(AccessDeniedException::class);
+
+        $client = static::createClient();
+        $user = UserFactory::createOne();
+        $client->loginUser($user->object());
+        $contract = ContractFactory::createOne([
+            'maxHours' => 10,
+        ]);
+
+        $client->catchExceptions(false);
+        $client->request('POST', "/contracts/{$contract->getUid()}/max-hours/edit", [
+            '_csrf_token' => $this->generateCsrfToken($client, 'update contract max hours'),
+            'additionalHours' => 5,
+        ]);
+    }
+}
diff --git a/translations/messages+intl-icu.en_GB.yaml b/translations/messages+intl-icu.en_GB.yaml
index c3d2de5d..fe78ba70 100644
--- a/translations/messages+intl-icu.en_GB.yaml
+++ b/translations/messages+intl-icu.en_GB.yaml
@@ -56,6 +56,8 @@ contracts.index.number: '{count, plural, =0 {No contracts} one {1 contract} othe
 contracts.index.tickets: '{count, plural, =0 {No tickets} one {1 ticket} other {# tickets}}'
 contracts.index.title: Contracts
 contracts.max_hours: 'Max number of hours'
+contracts.max_hours.edit.additional_hours: 'Number of additional hours'
+contracts.max_hours.edit.title: 'Extend the number of hours of the contract'
 contracts.name: Name
 contracts.new.billing_interval: 'Billing interval in minutes'
 contracts.new.billing_interval.caption: 'The time spent on tickets will be rounded up for billing purposes (e.g. for 15 minutes of time spent, 30 minutes will be deducted for a corresponding billing interval).'
@@ -63,6 +65,7 @@ contracts.new.submit: 'Create the contract'
 contracts.new.title: 'New contract'
 contracts.notes: 'Private notes'
 contracts.show.billing_interval: 'Billing interval: {count, plural, one {1 minute} other {# minutes}}'
+contracts.show.extend: Extend
 contracts.show.notes_confidential: confidential
 contracts.show.renew: Renew
 contracts.start_at: 'Start on'
diff --git a/translations/messages+intl-icu.fr_FR.yaml b/translations/messages+intl-icu.fr_FR.yaml
index 4458901f..435954c7 100644
--- a/translations/messages+intl-icu.fr_FR.yaml
+++ b/translations/messages+intl-icu.fr_FR.yaml
@@ -56,6 +56,8 @@ contracts.index.number: '{count, plural, =0 {Aucun contrat} one {1 contrat} othe
 contracts.index.tickets: '{count, plural, =0 {Aucun ticket} one {1 ticket} other {# tickets}}'
 contracts.index.title: Contrats
 contracts.max_hours: 'Nombre max. d’heures'
+contracts.max_hours.edit.additional_hours: 'Nombre d’heures supplémentaires'
+contracts.max_hours.edit.title: 'Rallonger le nombre d’heures du contrat'
 contracts.name: Nom
 contracts.new.billing_interval: 'Intervalle de facturation en minutes'
 contracts.new.billing_interval.caption: 'Le temps passé sur les tickets sera arrondi pour le décompte de la facturation (ex. pour 15 minutes de temps passés, 30 minutes seront décomptés pour un intervalle de facturation correspondant).'
@@ -63,6 +65,7 @@ contracts.new.submit: 'Créer le contrat'
 contracts.new.title: 'Nouveau contrat'
 contracts.notes: 'Notes privées'
 contracts.show.billing_interval: "Intervalle de facturation\_: {count, plural, one {1 minute} other {# minutes}}"
+contracts.show.extend: Rallonger
 contracts.show.notes_confidential: confidentielles
 contracts.show.renew: Renouveler
 contracts.start_at: 'Démarre le'