diff --git a/README.md b/README.md
index 36682e8..fcdd640 100644
--- a/README.md
+++ b/README.md
@@ -12,4 +12,7 @@ Make your own Time and Temperature phone number / sms service!
 - Copy the time-temp.inc.php.dist file to time-temp.inc.php and modify with your Twilio and WUnderground details.
 - Access time-temp.php to ensure it's working (should generate XML.)
 - Set your Twilio phone number(s) to send an HTTP POST WebHook to the time-temp.php public URL.
+  - To do SMS, use the `?type` variable like this:
+    - Voice Webhook: `http://your.server.here/time-temp.php?type=voice`
+    - SMS Webhook: `http://your.server.here/time-temp.php?type=sms`
 - Call/text the number to test!