diff --git a/lib/routes/api/speech-credentials.js b/lib/routes/api/speech-credentials.js
index 28eff1e..64cdbdd 100644
--- a/lib/routes/api/speech-credentials.js
+++ b/lib/routes/api/speech-credentials.js
@@ -747,7 +747,8 @@ router.get('/:sid/test', async(req, res) => {
       }
       if (cred.use_for_stt) {
         try {
-          await testMicrosoftStt(logger, {api_key, region, use_custom_stt, custom_stt_endpoint_url});
+          await testMicrosoftStt(logger,
+            {api_key, region, use_custom_stt, custom_stt_endpoint, custom_stt_endpoint_url});
           results.stt.status = 'ok';
           SpeechCredential.sttTestResult(sid, true);
         } catch (err) {
diff --git a/lib/utils/speech-utils.js b/lib/utils/speech-utils.js
index 8ee8cbd..4e0498b 100644
--- a/lib/utils/speech-utils.js
+++ b/lib/utils/speech-utils.js
@@ -262,10 +262,19 @@ const testDeepgramStt = async(logger, credentials) => {
 };
 
 const testMicrosoftStt = async(logger, credentials) => {
-  const {api_key, region, use_custom_stt, custom_stt_endpoint_url} = credentials;
-  const speechConfig = use_custom_stt ? sdk.SpeechConfig.fromEndpoint(
-    new URL(custom_stt_endpoint_url), api_key) :
-    sdk.SpeechConfig.fromSubscription(api_key, region);
+  const {api_key, region, use_custom_stt, custom_stt_endpoint, custom_stt_endpoint_url} = credentials;
+  // custom_stt_endpoint_url is a custom service host URL (fromEndpoint),
+  // custom_stt_endpoint is a custom model/deployment id (endpointId on a region-based config)
+  let speechConfig;
+  if (use_custom_stt && custom_stt_endpoint_url) {
+    speechConfig = sdk.SpeechConfig.fromEndpoint(new URL(custom_stt_endpoint_url), api_key);
+  }
+  else {
+    speechConfig = sdk.SpeechConfig.fromSubscription(api_key, region);
+    if (use_custom_stt && custom_stt_endpoint) {
+      speechConfig.endpointId = custom_stt_endpoint;
+    }
+  }
   const audioConfig = sdk.AudioConfig.fromWavFileInput(fs.readFileSync(`${__dirname}/../../data/test_audio.wav`));
   speechConfig.speechRecognitionLanguage = 'en-US';