diff --git a/src/BaseId.php b/src/BaseId.php
new file mode 100644
index 0000000..bbfc87f
--- /dev/null
+++ b/src/BaseId.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace Bulldog\id;
+
+class BaseId
+{
+    protected function encode($input)
+    {
+        return rtrim(strtr(base64_encode($input), '+/', '-_'), '=');
+    }
+}
diff --git a/src/IncrementalId.php b/src/IncrementalId.php
new file mode 100644
index 0000000..7a2ae4b
--- /dev/null
+++ b/src/IncrementalId.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace Bulldog\id;
+
+use Bulldog\id\Contracts\ObjectIdInterface;
+
+class IncrementalId extends BaseId implements ObjectIdInterface
+{
+    protected $prefix;
+    protected $id;
+
+    public function __construct(string $prefix = '')
+    {
+        $this->prefix = $prefix;
+    }
+
+    public function create(...$ids)
+    {
+        $this->id = '';
+        foreach($ids as $i) {
+            $this->id .= $this->encode($i);
+        }
+        return $this->id;
+    }
+
+    public function get($length)
+    {
+        return $this->prefix . substr($this->id, 0, $length);
+    }
+
+    public function setPrefix(string $prefix)
+    {
+        $this->prefix = $prefix;
+    }
+}
diff --git a/src/ObjectId.php b/src/ObjectId.php
index e49a9c2..d32c217 100644
--- a/src/ObjectId.php
+++ b/src/ObjectId.php
@@ -1,51 +1,47 @@
 <?php
 
-namespace Bulldog\id
-{
-    class ObjectId implements \Bulldog\id\Contracts\ObjectIdInterface
-    {
-        protected $prefix;
+namespace Bulldog\id;
 
-        public function __construct(string $prefix = '')
-        {
-            $this->prefix = $prefix;
-        }
+use Bulldog\id\Contracts\ObjectIdInterface;
 
-        public function get($length)
-        {
-            $parts = [];
+class ObjectId extends BaseId implements ObjectIdInterface
+{
+    protected $prefix;
 
-            // By using floor and ceil, if we divide an odd number by 2
-            // we only get whole numbers that add up to the length.
-            $parts[0] = $this->bucket(floor($length / 2));
-            $parts[1] = $this->random(ceil($length / 2));
+    public function __construct(string $prefix = '')
+    {
+        $this->prefix = $prefix;
+    }
 
-            $id = $parts[0].$parts[1];
+    public function get($length)
+    {
+        $parts = [];
 
-            return $this->prefix . $id;
-        }
+        // By using floor and ceil, if we divide an odd number by 2
+        // we only get whole numbers that add up to the length.
+        $parts[0] = $this->bucket(floor($length / 2));
+        $parts[1] = $this->random(ceil($length / 2));
 
-        public function setPrefix(string $prefix)
-        {
-            $this->prefix = $prefix;
-        }
+        $id = $parts[0].$parts[1];
 
-        protected function bucket($length)
-        {
-            $seconds = time() - mktime(0, 0, 0, 1, 1, date('Y'));
-            $secondsEncoded = $this->encode($seconds);
+        return $this->prefix . $id;
+    }
 
-            return substr($secondsEncoded, 0, $length);
-        }
+    public function setPrefix(string $prefix)
+    {
+        $this->prefix = $prefix;
+    }
+
+    protected function bucket($length)
+    {
+        $seconds = time() - mktime(0, 0, 0, 1, 1, date('Y'));
+        $secondsEncoded = $this->encode($seconds);
 
-        protected function random($length)
-        {
-            return substr($this->encode(random_bytes($length)), 0, $length);
-        }
+        return substr($secondsEncoded, 0, $length);
+    }
 
-        protected function encode($input)
-        {
-            return rtrim(strtr(base64_encode($input), '+/', '-_'), '=');
-        }
+    protected function random($length)
+    {
+        return substr($this->encode(random_bytes($length)), 0, $length);
     }
 }
diff --git a/tests/IdTests.php b/tests/IdTests.php
index 660d08b..b736504 100644
--- a/tests/IdTests.php
+++ b/tests/IdTests.php
@@ -75,4 +75,13 @@ public function testUsingSetPrefixMethod()
             $this->assertFalse($result);
         }
     }
+
+    public function testIncrementalId()
+    {
+        $iId = new \Bulldog\id\IncrementalId;
+
+        $id = $iId->create(4, 'dog', 9);
+        $this->assertEquals('NAZG9nOQ', $id);
+        $this->assertEquals('NAZG', $iId->get(4));
+    }
 }