diff --git a/src/base-apis.js b/src/base-apis.js
index 3dc8ced2a..2892d9af7 100644
--- a/src/base-apis.js
+++ b/src/base-apis.js
@@ -1803,10 +1803,11 @@ MatrixBaseApis.prototype.registerWithIdentityServer = function(hsOpenIdToken) {
 };
 
 /**
- * Requests an email verification token directly from an Identity Server.
+ * Requests an email verification token directly from an identity server.
  *
- * Note that the Homeserver offers APIs to proxy this API for specific
- * situations, allowing for better feedback to the user.
+ * This API is used as part of binding an email for discovery on an identity
+ * server. The validation data that results should be passed to the
+ * `bindThreePid` method to complete the binding process.
  *
  * @param {string} email The email address to request a token for
  * @param {string} clientSecret A secret binary string generated by the client.
@@ -1818,12 +1819,12 @@ MatrixBaseApis.prototype.registerWithIdentityServer = function(hsOpenIdToken) {
  * @param {string} nextLink Optional If specified, the client will be redirected
  *                 to this link after validation.
  * @param {module:client.callback} callback Optional.
- * @param {string} identityAccessToken The `access_token` field of the Identity
- * Server `/account/register` response (see {@link registerWithIdentityServer}).
+ * @param {string} identityAccessToken The `access_token` field of the identity
+ * server `/account/register` response (see {@link registerWithIdentityServer}).
  *
  * @return {module:client.Promise} Resolves: TODO
  * @return {module:http-api.MatrixError} Rejects: with an error response.
- * @throws Error if no Identity Server is set
+ * @throws Error if no identity server is set
  */
 MatrixBaseApis.prototype.requestEmailToken = async function(
     email,
@@ -1864,6 +1865,74 @@ MatrixBaseApis.prototype.requestEmailToken = async function(
     }
 };
 
+/**
+ * Requests a MSISDN verification token directly from an identity server.
+ *
+ * This API is used as part of binding a MSISDN for discovery on an identity
+ * server. The validation data that results should be passed to the
+ * `bindThreePid` method to complete the binding process.
+ *
+ * @param {string} phoneCountry The ISO 3166-1 alpha-2 code for the country in
+ *                 which phoneNumber should be parsed relative to.
+ * @param {string} phoneNumber The phone number, in national or international
+ *                 format
+ * @param {string} clientSecret A secret binary string generated by the client.
+ *                 It is recommended this be around 16 ASCII characters.
+ * @param {number} sendAttempt If an identity server sees a duplicate request
+ *                 with the same sendAttempt, it will not send another SMS.
+ *                 To request another SMS to be sent, use a larger value for
+ *                 the sendAttempt param as was used in the previous request.
+ * @param {string} nextLink Optional If specified, the client will be redirected
+ *                 to this link after validation.
+ * @param {module:client.callback} callback Optional.
+ * @param {string} identityAccessToken The `access_token` field of the Identity
+ * Server `/account/register` response (see {@link registerWithIdentityServer}).
+ *
+ * @return {module:client.Promise} Resolves: TODO
+ * @return {module:http-api.MatrixError} Rejects: with an error response.
+ * @throws Error if no identity server is set
+ */
+MatrixBaseApis.prototype.requestMsisdnToken = async function(
+    phoneCountry,
+    phoneNumber,
+    clientSecret,
+    sendAttempt,
+    nextLink,
+    callback,
+    identityAccessToken,
+) {
+    const params = {
+        client_secret: clientSecret,
+        country: phoneCountry,
+        phone_number: phoneNumber,
+        send_attempt: sendAttempt,
+        next_link: nextLink,
+    };
+
+    try {
+        const response = await this._http.idServerRequest(
+            undefined, "POST", "/validate/msisdn/requestToken",
+            params, httpApi.PREFIX_IDENTITY_V2, identityAccessToken,
+        );
+        // TODO: Fold callback into above call once v1 path below is removed
+        if (callback) callback(null, response);
+        return response;
+    } catch (err) {
+        if (err.cors === "rejected" || err.httpStatus === 404) {
+            // Fall back to deprecated v1 API for now
+            // TODO: Remove this path once v2 is only supported version
+            // See https://github.com/vector-im/riot-web/issues/10443
+            logger.warn("IS doesn't support v2, falling back to deprecated v1");
+            return await this._http.idServerRequest(
+                callback, "POST", "/validate/msisdn/requestToken",
+                params, httpApi.PREFIX_IDENTITY_V1,
+            );
+        }
+        if (callback) callback(err);
+        throw err;
+    }
+};
+
 /**
  * Submits an MSISDN token to the identity server
  *