diff --git a/src/AddThreepid.js b/src/AddThreepid.js
index 3b66b1d7ee..84fa07ff4b 100644
--- a/src/AddThreepid.js
+++ b/src/AddThreepid.js
@@ -35,6 +35,8 @@ import IdentityAuthClient from './IdentityAuthClient';
 export default class AddThreepid {
     constructor() {
         this.clientSecret = MatrixClientPeg.get().generateClientSecret();
+        this.sessionId = null;
+        this.submitUrl = null;
     }
 
     /**
@@ -101,6 +103,7 @@ export default class AddThreepid {
             phoneCountry, phoneNumber, this.clientSecret, 1,
         ).then((res) => {
             this.sessionId = res.sid;
+            this.submitUrl = res.submit_url;
             return res;
         }, function(err) {
             if (err.errcode === 'M_THREEPID_IN_USE') {
@@ -198,12 +201,23 @@ export default class AddThreepid {
     async haveMsisdnToken(msisdnToken) {
         const authClient = new IdentityAuthClient();
         const identityAccessToken = await authClient.getAccessToken();
-        const result = await MatrixClientPeg.get().submitMsisdnToken(
-            this.sessionId,
-            this.clientSecret,
-            msisdnToken,
-            identityAccessToken,
-        );
+
+        let result;
+        if (this.submitUrl) {
+            result = await MatrixClientPeg.get().submitMsisdnTokenOtherUrl(
+                this.submitUrl,
+                this.sessionId,
+                this.clientSecret,
+                msisdnToken,
+            );
+        } else {
+            result = await MatrixClientPeg.get().submitMsisdnToken(
+                this.sessionId,
+                this.clientSecret,
+                msisdnToken,
+                identityAccessToken,
+            );
+        }
         if (result.errcode) {
             throw result;
         }