diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 4544de821d..aa5d89a9ac 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -912,7 +912,7 @@ class AuthHandler(BaseHandler):
         )
 
     @defer.inlineCallbacks
-    def delete_threepid(self, user_id, medium, address):
+    def delete_threepid(self, user_id, medium, address, id_server=None):
         """Attempts to unbind the 3pid on the identity servers and deletes it
         from the local database.
 
@@ -920,6 +920,10 @@ class AuthHandler(BaseHandler):
             user_id (str)
             medium (str)
             address (str)
+            id_server (str|None): Use the given identity server when unbinding
+                any threepids. If None then will attempt to unbind using the
+                identity server specified when binding (if known).
+
 
         Returns:
             Deferred[bool]: Returns True if successfully unbound the 3pid on
@@ -937,6 +941,7 @@ class AuthHandler(BaseHandler):
             {
                 'medium': medium,
                 'address': address,
+                'id_server': id_server,
             },
         )
 
diff --git a/synapse/handlers/deactivate_account.py b/synapse/handlers/deactivate_account.py
index 97d3f31d98..101879f89f 100644
--- a/synapse/handlers/deactivate_account.py
+++ b/synapse/handlers/deactivate_account.py
@@ -43,12 +43,15 @@ class DeactivateAccountHandler(BaseHandler):
         hs.get_reactor().callWhenRunning(self._start_user_parting)
 
     @defer.inlineCallbacks
-    def deactivate_account(self, user_id, erase_data):
+    def deactivate_account(self, user_id, erase_data, id_server=None):
         """Deactivate a user's account
 
         Args:
             user_id (str): ID of user to be deactivated
             erase_data (bool): whether to GDPR-erase the user's data
+            id_server (str|None): Use the given identity server when unbinding
+                any threepids. If None then will attempt to unbind using the
+                identity server specified when binding (if known).
 
         Returns:
             Deferred[bool]: True if identity server supports removing
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py
index 765b16d1d9..4c127ba125 100644
--- a/synapse/handlers/identity.py
+++ b/synapse/handlers/identity.py
@@ -159,11 +159,14 @@ class IdentityHandler(BaseHandler):
             Deferred[bool]: True on success, otherwise False if the identity
             server doesn't support unbinding
         """
-        id_servers = yield self.store.get_id_servers_user_bound(
-            user_id=mxid,
-            medium=threepid["medium"],
-            address=threepid["address"],
-        )
+        if threepid.get("id_server"):
+            id_servers = [threepid["id_server"]]
+        else:
+            id_servers = yield self.store.get_id_servers_user_bound(
+                user_id=mxid,
+                medium=threepid["medium"],
+                address=threepid["address"],
+            )
 
         # We don't know where to unbind, so we don't have a choice but to return
         if not id_servers:
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 37b32dd37b..50a434a507 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -215,6 +215,7 @@ class DeactivateAccountRestServlet(RestServlet):
         )
         result = yield self._deactivate_account_handler.deactivate_account(
             requester.user.to_string(), erase,
+            id_server=body.get("id_server"),
         )
         if result:
             id_server_unbind_result = "success"
@@ -380,7 +381,7 @@ class ThreepidDeleteRestServlet(RestServlet):
 
         try:
             ret = yield self.auth_handler.delete_threepid(
-                user_id, body['medium'], body['address']
+                user_id, body['medium'], body['address'], body.get("id_server"),
             )
         except Exception:
             # NB. This endpoint should succeed if there is nothing to