diff --git a/userapi/api/api.go b/userapi/api/api.go
index 8d7f783de..49cdb404d 100644
--- a/userapi/api/api.go
+++ b/userapi/api/api.go
@@ -50,6 +50,7 @@ type KeyserverUserAPI interface {
 
 type RoomserverUserAPI interface {
 	QueryAccountData(ctx context.Context, req *QueryAccountDataRequest, res *QueryAccountDataResponse) error
+	QueryAccountByLocalpart(ctx context.Context, req *QueryAccountByLocalpartRequest, res *QueryAccountByLocalpartResponse) (err error)
 }
 
 // api functions required by the media api
@@ -654,3 +655,11 @@ type PerformForgetThreePIDRequest QueryLocalpartForThreePIDRequest
 type PerformSaveThreePIDAssociationRequest struct {
 	ThreePID, Localpart, Medium string
 }
+
+type QueryAccountByLocalpartRequest struct {
+	Localpart string
+}
+
+type QueryAccountByLocalpartResponse struct {
+	Account *Account
+}
diff --git a/userapi/api/api_trace.go b/userapi/api/api_trace.go
index 90834f7e3..deee3d080 100644
--- a/userapi/api/api_trace.go
+++ b/userapi/api/api_trace.go
@@ -204,6 +204,12 @@ func (t *UserInternalAPITrace) PerformSaveThreePIDAssociation(ctx context.Contex
 	return err
 }
 
+func (t *UserInternalAPITrace) QueryAccountByLocalpart(ctx context.Context, req *QueryAccountByLocalpartRequest, res *QueryAccountByLocalpartResponse) error {
+	err := t.Impl.QueryAccountByLocalpart(ctx, req, res)
+	util.GetLogger(ctx).Infof("QueryAccountByLocalpart req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
 func js(thing interface{}) string {
 	b, err := json.Marshal(thing)
 	if err != nil {
diff --git a/userapi/internal/api.go b/userapi/internal/api.go
index 9ca76965d..1c6f5c43a 100644
--- a/userapi/internal/api.go
+++ b/userapi/internal/api.go
@@ -536,6 +536,11 @@ func (a *UserInternalAPI) QueryAccessToken(ctx context.Context, req *api.QueryAc
 	return nil
 }
 
+func (a *UserInternalAPI) QueryAccountByLocalpart(ctx context.Context, req *api.QueryAccountByLocalpartRequest, res *api.QueryAccountByLocalpartResponse) (err error) {
+	res.Account, err = a.DB.GetAccountByLocalpart(ctx, req.Localpart)
+	return
+}
+
 // Return the appservice 'device' or nil if the token is not an appservice. Returns an error if there was a problem
 // creating a 'device'.
 func (a *UserInternalAPI) queryAppServiceToken(ctx context.Context, token, appServiceUserID string) (*api.Device, error) {
diff --git a/userapi/inthttp/client.go b/userapi/inthttp/client.go
index aa5d46d9f..33f89af68 100644
--- a/userapi/inthttp/client.go
+++ b/userapi/inthttp/client.go
@@ -60,6 +60,7 @@ const (
 	QueryAccountByPasswordPath     = "/userapi/queryAccountByPassword"
 	QueryLocalpartForThreePIDPath  = "/userapi/queryLocalpartForThreePID"
 	QueryThreePIDsForLocalpartPath = "/userapi/queryThreePIDsForLocalpart"
+	QueryAccountByLocalpartPath    = "/userapi/queryAccountType"
 )
 
 // NewUserAPIClient creates a UserInternalAPI implemented by talking to a HTTP POST API.
@@ -439,3 +440,14 @@ func (h *httpUserInternalAPI) PerformSaveThreePIDAssociation(
 		h.httpClient, ctx, request, response,
 	)
 }
+
+func (h *httpUserInternalAPI) QueryAccountByLocalpart(
+	ctx context.Context,
+	req *api.QueryAccountByLocalpartRequest,
+	res *api.QueryAccountByLocalpartResponse,
+) error {
+	return httputil.CallInternalRPCAPI(
+		"QueryAccountByLocalpart", h.apiURL+QueryAccountByLocalpartPath,
+		h.httpClient, ctx, req, res,
+	)
+}
diff --git a/userapi/inthttp/server.go b/userapi/inthttp/server.go
index 99148b760..1d9c5af67 100644
--- a/userapi/inthttp/server.go
+++ b/userapi/inthttp/server.go
@@ -197,4 +197,9 @@ func AddRoutes(internalAPIMux *mux.Router, s api.UserInternalAPI) {
 		PerformSaveThreePIDAssociationPath,
 		httputil.MakeInternalRPCAPI("UserAPIPerformSaveThreePIDAssociation", s.PerformSaveThreePIDAssociation),
 	)
+
+	internalAPIMux.Handle(
+		QueryAccountByLocalpartPath,
+		httputil.MakeInternalRPCAPI("AccountByLocalpart", s.QueryAccountByLocalpart),
+	)
 }