diff --git a/app/Services/Allocations/FindAssignableAllocationService.php b/app/Services/Allocations/FindAssignableAllocationService.php
index ed3638265..6f523663a 100644
--- a/app/Services/Allocations/FindAssignableAllocationService.php
+++ b/app/Services/Allocations/FindAssignableAllocationService.php
@@ -5,7 +5,6 @@ namespace Pterodactyl\Services\Allocations;
 use Webmozart\Assert\Assert;
 use Pterodactyl\Models\Server;
 use Pterodactyl\Models\Allocation;
-use Pterodactyl\Exceptions\DisplayException;
 use Pterodactyl\Exceptions\Service\Allocation\AutoAllocationNotEnabledException;
 use Pterodactyl\Exceptions\Service\Allocation\NoAutoAllocationSpaceAvailableException;
 
@@ -42,7 +41,7 @@ class FindAssignableAllocationService
      */
     public function handle(Server $server)
     {
-        if (!config('pterodactyl.client_features.allocations.enabled')) {
+        if (! config('pterodactyl.client_features.allocations.enabled')) {
             throw new AutoAllocationNotEnabledException;
         }
 
@@ -64,6 +63,10 @@ class FindAssignableAllocationService
     }
 
     /**
+     * Create a new allocation on the server's node with a random port from the defined range
+     * in the settings. If there are no matches in that range, or something is wrong with the
+     * range information provided an exception will be raised.
+     *
      * @param \Pterodactyl\Models\Server $server
      * @return \Pterodactyl\Models\Allocation
      *
@@ -78,7 +81,7 @@ class FindAssignableAllocationService
         $start = config('pterodactyl.client_features.allocations.range_start', null);
         $end = config('pterodactyl.client_features.allocations.range_end', null);
 
-        if (!$start || !$end) {
+        if (! $start || ! $end) {
             throw new NoAutoAllocationSpaceAvailableException;
         }
 
diff --git a/tests/Integration/Services/Allocations/FindAssignableAllocationServiceTest.php b/tests/Integration/Services/Allocations/FindAssignableAllocationServiceTest.php
new file mode 100644
index 000000000..ce49a1873
--- /dev/null
+++ b/tests/Integration/Services/Allocations/FindAssignableAllocationServiceTest.php
@@ -0,0 +1,179 @@
+<?php
+
+namespace Pterodactyl\Tests\Integration\Services\Allocations;
+
+use Exception;
+use InvalidArgumentException;
+use Pterodactyl\Models\Allocation;
+use Pterodactyl\Tests\Integration\IntegrationTestCase;
+use Pterodactyl\Services\Allocations\FindAssignableAllocationService;
+use Pterodactyl\Exceptions\Service\Allocation\AutoAllocationNotEnabledException;
+use Pterodactyl\Exceptions\Service\Allocation\NoAutoAllocationSpaceAvailableException;
+
+class FindAssignableAllocationServiceTest extends IntegrationTestCase
+{
+    /**
+     * Setup tests.
+     */
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        config()->set('pterodactyl.client_features.allocations.enabled', true);
+        config()->set('pterodactyl.client_features.allocations.range_start', 0);
+        config()->set('pterodactyl.client_features.allocations.range_end', 0);
+    }
+
+    /**
+     * Test that an unassigned allocation is prefered rather than creating an entirely new
+     * allocation for the server.
+     */
+    public function testExistingAllocationIsPreferred()
+    {
+        $server = $this->createServerModel();
+
+        $created = factory(Allocation::class)->create([
+            'node_id' => $server->node_id,
+            'ip' => $server->allocation->ip,
+        ]);
+
+        $response = $this->getService()->handle($server);
+
+        $this->assertSame($created->id, $response->id);
+        $this->assertSame($server->allocation->ip, $response->ip);
+        $this->assertSame($server->node_id, $response->node_id);
+        $this->assertSame($server->id, $response->server_id);
+        $this->assertNotSame($server->allocation_id, $response->id);
+    }
+
+    /**
+     * Test that a new allocation is created if there is not a free one available.
+     */
+    public function testNewAllocationIsCreatedIfOneIsNotFound()
+    {
+        $server = $this->createServerModel();
+        config()->set('pterodactyl.client_features.allocations.range_start', 5000);
+        config()->set('pterodactyl.client_features.allocations.range_end', 5005);
+
+        $response = $this->getService()->handle($server);
+        $this->assertSame($server->id, $response->server_id);
+        $this->assertSame($server->allocation->ip, $response->ip);
+        $this->assertSame($server->node_id, $response->node_id);
+        $this->assertNotSame($server->allocation_id, $response->id);
+        $this->assertTrue($response->port >= 5000 && $response->port <= 5005);
+    }
+
+    /**
+     * Test that a currently assigned port is never assigned to a server.
+     */
+    public function testOnlyPortNotInUseIsCreated()
+    {
+        $server = $this->createServerModel();
+        $server2 = $this->createServerModel(['node_id' => $server->node_id]);
+
+        config()->set('pterodactyl.client_features.allocations.range_start', 5000);
+        config()->set('pterodactyl.client_features.allocations.range_end', 5001);
+
+        factory(Allocation::class)->create([
+            'server_id' => $server2->id,
+            'node_id' => $server->node_id,
+            'ip' => $server->allocation->ip,
+            'port' => 5000,
+        ]);
+
+        $response = $this->getService()->handle($server);
+        $this->assertSame(5001, $response->port);
+    }
+
+    public function testExceptionIsThrownIfNoMoreAllocationsCanBeCreatedInRange()
+    {
+        $server = $this->createServerModel();
+        $server2 = $this->createServerModel(['node_id' => $server->node_id]);
+        config()->set('pterodactyl.client_features.allocations.range_start', 5000);
+        config()->set('pterodactyl.client_features.allocations.range_end', 5005);
+
+        for ($i = 5000; $i <= 5005; $i++) {
+            factory(Allocation::class)->create([
+                'ip' => $server->allocation->ip,
+                'port' => $i,
+                'node_id' => $server->node_id,
+                'server_id' => $server2->id,
+            ]);
+        }
+
+        $this->expectException(NoAutoAllocationSpaceAvailableException::class);
+        $this->expectExceptionMessage('Cannot assign additional allocation: no more space available on node.');
+
+        $this->getService()->handle($server);
+    }
+
+    /**
+     * Test that we only auto-allocate from the current server's IP address space, and not a random
+     * IP address available on that node.
+     */
+    public function testExceptionIsThrownIfOnlyFreePortIsOnADifferentIp()
+    {
+        $server = $this->createServerModel();
+
+        factory(Allocation::class)->times(5)->create(['node_id' => $server->node_id]);
+
+        $this->expectException(NoAutoAllocationSpaceAvailableException::class);
+        $this->expectExceptionMessage('Cannot assign additional allocation: no more space available on node.');
+
+        $this->getService()->handle($server);
+    }
+
+    public function testExceptionIsThrownIfStartOrEndRangeIsNotDefined()
+    {
+        $server = $this->createServerModel();
+
+        $this->expectException(NoAutoAllocationSpaceAvailableException::class);
+        $this->expectExceptionMessage('Cannot assign additional allocation: no more space available on node.');
+
+        $this->getService()->handle($server);
+    }
+
+    public function testExceptionIsThrownIfStartOrEndRangeIsNotNumeric()
+    {
+        $server = $this->createServerModel();
+        config()->set('pterodactyl.client_features.allocations.range_start', 'hodor');
+        config()->set('pterodactyl.client_features.allocations.range_end', 10);
+
+        try {
+            $this->getService()->handle($server);
+            $this->assertTrue(false, 'This assertion should not be reached.');
+        } catch (Exception $exception) {
+            $this->assertInstanceOf(InvalidArgumentException::class, $exception);
+            $this->assertSame('Expected an integerish value. Got: string', $exception->getMessage());
+        }
+
+        config()->set('pterodactyl.client_features.allocations.range_start', 10);
+        config()->set('pterodactyl.client_features.allocations.range_end', 'hodor');
+
+        try {
+            $this->getService()->handle($server);
+            $this->assertTrue(false, 'This assertion should not be reached.');
+        } catch (Exception $exception) {
+            $this->assertInstanceOf(InvalidArgumentException::class, $exception);
+            $this->assertSame('Expected an integerish value. Got: string', $exception->getMessage());
+        }
+    }
+
+    public function testExceptionIsThrownIfFeatureIsNotEnabled()
+    {
+        config()->set('pterodactyl.client_features.allocations.enabled', false);
+        $server = $this->createServerModel();
+
+        $this->expectException(AutoAllocationNotEnabledException::class);
+
+        $this->getService()->handle($server);
+    }
+
+    /**
+     * @return \Pterodactyl\Services\Allocations\FindAssignableAllocationService
+     */
+    private function getService()
+    {
+        return $this->app->make(FindAssignableAllocationService::class);
+    }
+}