diff --git a/.upgradenotes/MDL-84342-2025020311153786.yml b/.upgradenotes/MDL-84342-2025020311153786.yml
new file mode 100644
index 00000000000..8bf1a07c936
--- /dev/null
+++ b/.upgradenotes/MDL-84342-2025020311153786.yml
@@ -0,0 +1,7 @@
+issueNumber: MDL-84342
+notes:
+  core_sms:
+    - message: >-
+        Introducing a new function \core_sms\gateway::truncate_message() to truncate SMS message content
+        according to the length limit of the gateway.
+      type: improved
diff --git a/sms/classes/gateway.php b/sms/classes/gateway.php
index 22067dad9d9..1dba5c58802 100644
--- a/sms/classes/gateway.php
+++ b/sms/classes/gateway.php
@@ -34,6 +34,9 @@ use stdClass;
 abstract class gateway {
     use Cloneable;
 
+    /** @var int The maximum length of a message. */
+    protected const MESSAGE_LENGTH_LIMIT = 160 * 3;
+
     /** @var stdClass The configuration for this instance */
     public readonly stdClass $config;
 
@@ -128,4 +131,14 @@ abstract class gateway {
     public function update_message_statuses(array $messages): array {
         return array_map([$this, 'update_message_status'], $messages);
     }
+
+    /**
+     * Truncates the given message to fit the constraints.
+     *
+     * @param string $message The message to be truncated.
+     * @return string The truncated message.
+     */
+    public function truncate_message(string $message): string {
+        return \core_text::substr($message, 0, static::MESSAGE_LENGTH_LIMIT);
+    }
 }
diff --git a/sms/classes/manager.php b/sms/classes/manager.php
index a19445be205..ad2ef73f92d 100644
--- a/sms/classes/manager.php
+++ b/sms/classes/manager.php
@@ -27,9 +27,6 @@ use stdClass;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class manager {
-    /** @var int The maximum length of a message */
-    const MESSAGE_LENGTH_LIMIT = 160 * 3;
-
     /**
      * Create a new SMS manager.
      *
@@ -105,13 +102,12 @@ class manager {
             return $message;
         }
 
-        if (\core_text::strlen($message->content) > self::MESSAGE_LENGTH_LIMIT) {
-            $message = $message->with(status: message_status::MESSAGE_OVER_SIZE);
-        } else if ($gateway = $this->get_gateway_for_message($message, $gatewayid)) {
-            $message = $message->with(gatewayid: $gateway->id);
-            $message = $gateway->send(
-                message: $message,
+        if ($gateway = $this->get_gateway_for_message($message, $gatewayid)) {
+            $modifiedmessage = $message->with(
+                gatewayid: $gateway->id,
+                content: $gateway->truncate_message($message->content),
             );
+            $message = $gateway->send($modifiedmessage);
         } else {
             $message = $message->with(status: message_status::GATEWAY_NOT_AVAILABLE);
         }
diff --git a/sms/tests/fixtures/dummy_gateway.php b/sms/tests/fixtures/dummy_gateway.php
index 8cd43971595..f8c82bf75c6 100644
--- a/sms/tests/fixtures/dummy_gateway.php
+++ b/sms/tests/fixtures/dummy_gateway.php
@@ -26,6 +26,9 @@ use core_sms\message;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class gateway extends \core_sms\gateway {
+    /** @var int The maximum length of a message */
+    protected const MESSAGE_LENGTH_LIMIT = 160 * 1;
+
     #[\Override]
     public function send(message $message): message {
         return $message->with(
diff --git a/sms/tests/manager_test.php b/sms/tests/manager_test.php
index da4508e9d65..320dc9553c5 100644
--- a/sms/tests/manager_test.php
+++ b/sms/tests/manager_test.php
@@ -492,6 +492,39 @@ final class manager_test extends \advanced_testcase {
         $this->assertEmpty($message->gatewayid);
     }
 
+    /**
+     * Test the truncate content process while sending the SMS.
+     */
+    public function test_send_truncate_content(): void {
+        $this->resetAfterTest();
+
+        $config = new \stdClass();
+        $config->priority = 50;
+
+        $manager = \core\di::get(\core_sms\manager::class);
+        $manager->create_gateway_instance(
+            classname: \smsgateway_dummy\gateway::class,
+            name: 'dummy',
+            enabled: true,
+            config: $config,
+        );
+
+        $message = $manager->send(
+            recipientnumber: '+447123456789',
+            content: str_repeat('a', 161),
+            component: 'core',
+            messagetype: 'test',
+            recipientuserid: null,
+            async: false,
+        );
+
+        // Expected the message to be truncated with the length limit.
+        $this->assertEquals(
+            expected: str_repeat('a', 160), // 160 is the limit of the dummy gateway.
+            actual: $message->content,
+        );
+    }
+
     public function test_get_messages(): void {
         $db = $this->createStub(\moodle_database::class);
         $db->method('get_records')->willReturn([