diff --git a/includes/class-twp-twilio-api.php b/includes/class-twp-twilio-api.php
index 338e254..64eca03 100644
--- a/includes/class-twp-twilio-api.php
+++ b/includes/class-twp-twilio-api.php
@@ -278,10 +278,10 @@ class TWP_Twilio_API {
             foreach ($numbers as $number) {
                 $numbers_data[] = [
                     'sid' => $number->sid ?: '',
-                    'phoneNumber' => $number->phoneNumber ?: '',
-                    'friendlyName' => $number->friendlyName ?: $number->phoneNumber ?: 'Unknown',
-                    'voiceUrl' => $number->voiceUrl ?: '',
-                    'smsUrl' => $number->smsUrl ?: '',
+                    'phone_number' => $number->phoneNumber ?: '',
+                    'friendly_name' => $number->friendlyName ?: $number->phoneNumber ?: 'Unknown',
+                    'voice_url' => $number->voiceUrl ?: '',
+                    'sms_url' => $number->smsUrl ?: '',
                     'capabilities' => [
                         'voice' => $number->capabilities ? (bool)$number->capabilities->getVoice() : false,
                         'sms' => $number->capabilities ? (bool)$number->capabilities->getSms() : false,
@@ -327,11 +327,11 @@ class TWP_Twilio_API {
             $numbers_data = [];
             foreach ($numbers as $number) {
                 $numbers_data[] = [
-                    'phoneNumber' => $number->phoneNumber ?: '',
-                    'friendlyName' => $number->friendlyName ?: $number->phoneNumber ?: 'Available Number',
+                    'phone_number' => $number->phoneNumber ?: '',
+                    'friendly_name' => $number->friendlyName ?: $number->phoneNumber ?: 'Available Number',
                     'locality' => $number->locality ?: '',
                     'region' => $number->region ?: '',
-                    'postalCode' => $number->postalCode ?: '',
+                    'postal_code' => $number->postalCode ?: '',
                     'capabilities' => [
                         'voice' => $number->capabilities ? (bool)$number->capabilities->getVoice() : false,
                         'sms' => $number->capabilities ? (bool)$number->capabilities->getSms() : false,
@@ -378,10 +378,10 @@ class TWP_Twilio_API {
                 'success' => true,
                 'data' => [
                     'sid' => $number->sid,
-                    'phoneNumber' => $number->phoneNumber,
-                    'friendlyName' => $number->friendlyName,
-                    'voiceUrl' => $number->voiceUrl,
-                    'smsUrl' => $number->smsUrl
+                    'phone_number' => $number->phoneNumber,
+                    'friendly_name' => $number->friendlyName,
+                    'voice_url' => $number->voiceUrl,
+                    'sms_url' => $number->smsUrl
                 ]
             ];
         } catch (\Twilio\Exceptions\TwilioException $e) {
@@ -436,9 +436,9 @@ class TWP_Twilio_API {
                 'success' => true,
                 'data' => [
                     'sid' => $number->sid,
-                    'phoneNumber' => $number->phoneNumber,
-                    'voiceUrl' => $number->voiceUrl,
-                    'smsUrl' => $number->smsUrl
+                    'phone_number' => $number->phoneNumber,
+                    'voice_url' => $number->voiceUrl,
+                    'sms_url' => $number->smsUrl
                 ]
             ];
         } catch (\Twilio\Exceptions\TwilioException $e) {