diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/account_data.go b/src/github.com/matrix-org/dendrite/clientapi/routing/account_data.go
index bd387eb96..90bbe343e 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/account_data.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/account_data.go
@@ -15,22 +15,26 @@
 package routing
 
 import (
+	"context"
 	"io/ioutil"
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
 	"github.com/matrix-org/gomatrixserverlib"
-
 	"github.com/matrix-org/util"
 )
 
+// interface for database layer
+type accountsData interface {
+	SaveAccountData(context.Context, string, string, string, string) error
+}
+
 // SaveAccountData implements PUT /user/{userId}/[rooms/{roomId}/]account_data/{type}
 func SaveAccountData(
-	req *http.Request, accountDB *accounts.Database, device *authtypes.Device,
+	req *http.Request, accountDB accountsData, device *authtypes.Device,
 	userID string, roomID string, dataType string, syncProducer *producers.SyncAPIProducer,
 ) util.JSONResponse {
 	if req.Method != "PUT" {
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/createroom.go b/src/github.com/matrix-org/dendrite/clientapi/routing/createroom.go
index f7956d29a..07168666c 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/createroom.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/createroom.go
@@ -15,25 +15,29 @@
 package routing
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"strings"
 	"time"
 
-	"github.com/matrix-org/dendrite/roomserver/api"
-
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
 	"github.com/matrix-org/dendrite/common"
 	"github.com/matrix-org/dendrite/common/config"
+	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 	log "github.com/sirupsen/logrus"
 )
 
+// interface to Database Layer
+type createRoomData interface {
+	GetProfileByLocalpart(context.Context, string) (*authtypes.Profile, error)
+}
+
 // https://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-createroom
 type createRoomRequest struct {
 	Invite          []string               `json:"invite"`
@@ -116,7 +120,7 @@ type fledglingEvent struct {
 // CreateRoom implements /createRoom
 func CreateRoom(req *http.Request, device *authtypes.Device,
 	cfg config.Dendrite, producer *producers.RoomserverProducer,
-	accountDB *accounts.Database, aliasAPI api.RoomserverAliasAPI,
+	accountDB createRoomData, aliasAPI api.RoomserverAliasAPI,
 ) util.JSONResponse {
 	// TODO (#267): Check room ID doesn't clash with an existing one, and we
 	//              probably shouldn't be using pseudo-random strings, maybe GUIDs?
@@ -128,7 +132,7 @@ func CreateRoom(req *http.Request, device *authtypes.Device,
 // nolint: gocyclo
 func createRoom(req *http.Request, device *authtypes.Device,
 	cfg config.Dendrite, roomID string, producer *producers.RoomserverProducer,
-	accountDB *accounts.Database, aliasAPI api.RoomserverAliasAPI,
+	accountDB createRoomData, aliasAPI api.RoomserverAliasAPI,
 ) util.JSONResponse {
 	logger := util.GetLogger(req.Context())
 	userID := device.UserID
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/device.go b/src/github.com/matrix-org/dendrite/clientapi/routing/device.go
index 75df2e6e4..832a632c7 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/device.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/device.go
@@ -15,18 +15,25 @@
 package routing
 
 import (
+	"context"
 	"database/sql"
 	"encoding/json"
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/devices"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 )
 
+// interface to Database layer
+type deviceData interface {
+	GetDevicesByLocalpart(context.Context, string) ([]authtypes.Device, error)
+	GetDeviceByID(ctx context.Context, localpart, deviceID string) (*authtypes.Device, error)
+	UpdateDevice(context.Context, string, string, *string) error
+}
+
 type deviceJSON struct {
 	DeviceID string `json:"device_id"`
 	UserID   string `json:"user_id"`
@@ -42,7 +49,7 @@ type deviceUpdateJSON struct {
 
 // GetDeviceByID handles /device/{deviceID}
 func GetDeviceByID(
-	req *http.Request, deviceDB *devices.Database, device *authtypes.Device,
+	req *http.Request, deviceDB deviceData, device *authtypes.Device,
 	deviceID string,
 ) util.JSONResponse {
 	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
@@ -72,7 +79,7 @@ func GetDeviceByID(
 
 // GetDevicesByLocalpart handles /devices
 func GetDevicesByLocalpart(
-	req *http.Request, deviceDB *devices.Database, device *authtypes.Device,
+	req *http.Request, deviceDB deviceData, device *authtypes.Device,
 ) util.JSONResponse {
 	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
 	if err != nil {
@@ -103,7 +110,7 @@ func GetDevicesByLocalpart(
 
 // UpdateDeviceByID handles PUT on /devices/{deviceID}
 func UpdateDeviceByID(
-	req *http.Request, deviceDB *devices.Database, device *authtypes.Device,
+	req *http.Request, deviceDB deviceData, device *authtypes.Device,
 	deviceID string,
 ) util.JSONResponse {
 	if req.Method != "PUT" {
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/filter.go b/src/github.com/matrix-org/dendrite/clientapi/routing/filter.go
index 4b84e293d..cd822a90a 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/filter.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/filter.go
@@ -15,12 +15,11 @@
 package routing
 
 import (
+	"context"
+	"encoding/json"
 	"net/http"
 
-	"encoding/json"
-
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/gomatrix"
@@ -28,9 +27,15 @@ import (
 	"github.com/matrix-org/util"
 )
 
+// interface to database layer
+type filterData interface {
+	GetFilter(context.Context, string, string) ([]byte, error)
+	PutFilter(context.Context, string, []byte) (string, error)
+}
+
 // GetFilter implements GET /_matrix/client/r0/user/{userId}/filter/{filterId}
 func GetFilter(
-	req *http.Request, device *authtypes.Device, accountDB *accounts.Database, userID string, filterID string,
+	req *http.Request, device *authtypes.Device, accountDB filterData, userID string, filterID string,
 ) util.JSONResponse {
 	if req.Method != http.MethodGet {
 		return util.JSONResponse{
@@ -77,7 +82,7 @@ type filterResponse struct {
 
 //PutFilter implements POST /_matrix/client/r0/user/{userId}/filter
 func PutFilter(
-	req *http.Request, device *authtypes.Device, accountDB *accounts.Database, userID string,
+	req *http.Request, device *authtypes.Device, accountDB filterData, userID string,
 ) util.JSONResponse {
 	if req.Method != http.MethodPost {
 		return util.JSONResponse{
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/joinroom.go b/src/github.com/matrix-org/dendrite/clientapi/routing/joinroom.go
index aba49cd65..ab98aaa9a 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/joinroom.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/joinroom.go
@@ -15,13 +15,13 @@
 package routing
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"strings"
 	"time"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
@@ -33,6 +33,11 @@ import (
 	"github.com/matrix-org/util"
 )
 
+// interface to Database
+type joinRoomData interface {
+	GetProfileByLocalpart(context.Context, string) (*authtypes.Profile, error)
+}
+
 // JoinRoomByIDOrAlias implements the "/join/{roomIDOrAlias}" API.
 // https://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-join-roomidoralias
 func JoinRoomByIDOrAlias(
@@ -45,7 +50,7 @@ func JoinRoomByIDOrAlias(
 	queryAPI api.RoomserverQueryAPI,
 	aliasAPI api.RoomserverAliasAPI,
 	keyRing gomatrixserverlib.KeyRing,
-	accountDB *accounts.Database,
+	accountDB joinRoomData,
 ) util.JSONResponse {
 	var content map[string]interface{} // must be a JSON object
 	if resErr := httputil.UnmarshalJSONRequest(req, &content); resErr != nil {
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/login.go b/src/github.com/matrix-org/dendrite/clientapi/routing/login.go
index f48261ab2..b866df006 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/login.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/login.go
@@ -15,12 +15,12 @@
 package routing
 
 import (
+	"context"
 	"net/http"
 	"strings"
 
 	"github.com/matrix-org/dendrite/clientapi/auth"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/devices"
+	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/common/config"
@@ -28,6 +28,16 @@ import (
 	"github.com/matrix-org/util"
 )
 
+// interface to accounts database layer
+type loginAccountsData interface {
+	GetAccountByPassword(context.Context, string, string) (*authtypes.Account, error)
+}
+
+// interface to devices database layer
+type loginDevicesData interface {
+	CreateDevice(context.Context, string, *string, string, *string) (dev *authtypes.Device, returnErr error)
+}
+
 type loginFlows struct {
 	Flows []flow `json:"flows"`
 }
@@ -59,7 +69,7 @@ func passwordLogin() loginFlows {
 
 // Login implements GET and POST /login
 func Login(
-	req *http.Request, accountDB *accounts.Database, deviceDB *devices.Database,
+	req *http.Request, accountDB loginAccountsData, deviceDB loginDevicesData,
 	cfg config.Dendrite,
 ) util.JSONResponse {
 	if req.Method == "GET" { // TODO: support other forms of login other than password, depending on config options
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/logout.go b/src/github.com/matrix-org/dendrite/clientapi/routing/logout.go
index d03e7957f..d2d06f301 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/logout.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/logout.go
@@ -15,19 +15,25 @@
 package routing
 
 import (
+	"context"
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/devices"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 )
 
+//interface to devices database layer
+type logoutDevicesData interface {
+	RemoveDevice(context.Context, string, string) error
+	RemoveAllDevices(context.Context, string) error
+}
+
 // Logout handles POST /logout
 func Logout(
-	req *http.Request, deviceDB *devices.Database, device *authtypes.Device,
+	req *http.Request, deviceDB logoutDevicesData, device *authtypes.Device,
 ) util.JSONResponse {
 	if req.Method != "POST" {
 		return util.JSONResponse{
@@ -53,7 +59,7 @@ func Logout(
 
 // LogoutAll handles POST /logout/all
 func LogoutAll(
-	req *http.Request, deviceDB *devices.Database, device *authtypes.Device,
+	req *http.Request, deviceDB logoutDevicesData, device *authtypes.Device,
 ) util.JSONResponse {
 	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
 	if err != nil {
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/membership.go b/src/github.com/matrix-org/dendrite/clientapi/routing/membership.go
index 8e2e87ad3..4c2e45ed8 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/membership.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/membership.go
@@ -20,7 +20,6 @@ import (
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
@@ -29,16 +28,19 @@ import (
 	"github.com/matrix-org/dendrite/common/config"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
-
 	"github.com/matrix-org/util"
 )
 
+type membershipAccountsData interface {
+	GetProfileByLocalpart(context.Context, string) (*authtypes.Profile, error)
+}
+
 var errMissingUserID = errors.New("'user_id' must be supplied")
 
 // SendMembership implements PUT /rooms/{roomID}/(join|kick|ban|unban|leave|invite)
 // by building a m.room.member event then sending it to the room server
 func SendMembership(
-	req *http.Request, accountDB *accounts.Database, device *authtypes.Device,
+	req *http.Request, accountDB membershipAccountsData, device *authtypes.Device,
 	roomID string, membership string, cfg config.Dendrite,
 	queryAPI api.RoomserverQueryAPI, producer *producers.RoomserverProducer,
 ) util.JSONResponse {
@@ -111,7 +113,7 @@ func SendMembership(
 
 func buildMembershipEvent(
 	ctx context.Context,
-	body threepid.MembershipRequest, accountDB *accounts.Database,
+	body threepid.MembershipRequest, accountDB membershipAccountsData,
 	device *authtypes.Device, membership string, roomID string, cfg config.Dendrite,
 	queryAPI api.RoomserverQueryAPI,
 ) (*gomatrixserverlib.Event, error) {
@@ -156,7 +158,7 @@ func buildMembershipEvent(
 // Returns an error if the retrieval failed or if the first parameter isn't a
 // valid Matrix ID.
 func loadProfile(
-	ctx context.Context, userID string, cfg config.Dendrite, accountDB *accounts.Database,
+	ctx context.Context, userID string, cfg config.Dendrite, accountDB membershipAccountsData,
 ) (*authtypes.Profile, error) {
 	localpart, serverName, err := gomatrixserverlib.SplitID('@', userID)
 	if err != nil {
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/profile.go b/src/github.com/matrix-org/dendrite/clientapi/routing/profile.go
index ddbae50ca..894bb69bf 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/profile.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/profile.go
@@ -19,7 +19,6 @@ import (
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
@@ -27,13 +26,20 @@ import (
 	"github.com/matrix-org/dendrite/common/config"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
-
 	"github.com/matrix-org/util"
 )
 
+// interface to accounts database layer
+type profileAccountsData interface {
+	GetProfileByLocalpart(context.Context, string) (*authtypes.Profile, error)
+	SetAvatarURL(context.Context, string, string) error
+	GetMembershipsByLocalpart(context.Context, string) (memberships []authtypes.Membership, err error)
+	SetDisplayName(context.Context, string, string) error
+}
+
 // GetProfile implements GET /profile/{userID}
 func GetProfile(
-	req *http.Request, accountDB *accounts.Database, userID string,
+	req *http.Request, accountDB profileAccountsData, userID string,
 ) util.JSONResponse {
 	if req.Method != "GET" {
 		return util.JSONResponse{
@@ -62,7 +68,7 @@ func GetProfile(
 
 // GetAvatarURL implements GET /profile/{userID}/avatar_url
 func GetAvatarURL(
-	req *http.Request, accountDB *accounts.Database, userID string,
+	req *http.Request, accountDB profileAccountsData, userID string,
 ) util.JSONResponse {
 	localpart, _, err := gomatrixserverlib.SplitID('@', userID)
 	if err != nil {
@@ -84,7 +90,7 @@ func GetAvatarURL(
 
 // SetAvatarURL implements PUT /profile/{userID}/avatar_url
 func SetAvatarURL(
-	req *http.Request, accountDB *accounts.Database, device *authtypes.Device,
+	req *http.Request, accountDB profileAccountsData, device *authtypes.Device,
 	userID string, producer *producers.UserUpdateProducer, cfg *config.Dendrite,
 	rsProducer *producers.RoomserverProducer, queryAPI api.RoomserverQueryAPI,
 ) util.JSONResponse {
@@ -154,7 +160,7 @@ func SetAvatarURL(
 
 // GetDisplayName implements GET /profile/{userID}/displayname
 func GetDisplayName(
-	req *http.Request, accountDB *accounts.Database, userID string,
+	req *http.Request, accountDB profileAccountsData, userID string,
 ) util.JSONResponse {
 	localpart, _, err := gomatrixserverlib.SplitID('@', userID)
 	if err != nil {
@@ -176,7 +182,7 @@ func GetDisplayName(
 
 // SetDisplayName implements PUT /profile/{userID}/displayname
 func SetDisplayName(
-	req *http.Request, accountDB *accounts.Database, device *authtypes.Device,
+	req *http.Request, accountDB profileAccountsData, device *authtypes.Device,
 	userID string, producer *producers.UserUpdateProducer, cfg *config.Dendrite,
 	rsProducer *producers.RoomserverProducer, queryAPI api.RoomserverQueryAPI,
 ) util.JSONResponse {
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/register.go b/src/github.com/matrix-org/dendrite/clientapi/routing/register.go
index 77e875ec1..76bd078d4 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/register.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/register.go
@@ -34,8 +34,6 @@ import (
 
 	"github.com/matrix-org/dendrite/clientapi/auth"
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/devices"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -56,6 +54,15 @@ var (
 	validUsernameRegex = regexp.MustCompile(`^[0-9a-z_\-./]+$`)
 )
 
+type registerAccountsData interface {
+	CreateAccount(context.Context, string, string, string) (*authtypes.Account, error)
+	CheckAccountAvailability(context.Context, string) (bool, error)
+}
+
+type registerDevicesData interface {
+	CreateDevice(context.Context, string, *string, string, *string) (*authtypes.Device, error)
+}
+
 // registerRequest represents the submitted registration request.
 // It can be broken down into 2 sections: the auth dictionary and registration parameters.
 // Registration parameters vary depending on the request, and will need to remembered across
@@ -343,8 +350,8 @@ func validateApplicationService(
 // http://matrix.org/speculator/spec/HEAD/client_server/unstable.html#post-matrix-client-unstable-register
 func Register(
 	req *http.Request,
-	accountDB *accounts.Database,
-	deviceDB *devices.Database,
+	accountDB registerAccountsData,
+	deviceDB registerDevicesData,
 	cfg *config.Dendrite,
 ) util.JSONResponse {
 
@@ -408,8 +415,8 @@ func handleRegistrationFlow(
 	r registerRequest,
 	sessionID string,
 	cfg *config.Dendrite,
-	accountDB *accounts.Database,
-	deviceDB *devices.Database,
+	accountDB registerAccountsData,
+	deviceDB registerDevicesData,
 ) util.JSONResponse {
 	// TODO: Shared secret registration (create new user scripts)
 	// TODO: Enable registration config flag
@@ -490,8 +497,8 @@ func checkAndCompleteFlow(
 	r registerRequest,
 	sessionID string,
 	cfg *config.Dendrite,
-	accountDB *accounts.Database,
-	deviceDB *devices.Database,
+	accountDB registerAccountsData,
+	deviceDB registerDevicesData,
 ) util.JSONResponse {
 	if checkFlowCompleted(flow, cfg.Derived.Registration.Flows) {
 		// This flow was completed, registration can continue
@@ -511,8 +518,8 @@ func checkAndCompleteFlow(
 // LegacyRegister process register requests from the legacy v1 API
 func LegacyRegister(
 	req *http.Request,
-	accountDB *accounts.Database,
-	deviceDB *devices.Database,
+	accountDB registerAccountsData,
+	deviceDB registerDevicesData,
 	cfg *config.Dendrite,
 ) util.JSONResponse {
 	var r legacyRegisterRequest
@@ -589,8 +596,8 @@ func parseAndValidateLegacyLogin(req *http.Request, r *legacyRegisterRequest) *u
 
 func completeRegistration(
 	ctx context.Context,
-	accountDB *accounts.Database,
-	deviceDB *devices.Database,
+	accountDB registerAccountsData,
+	deviceDB registerDevicesData,
 	username, password, appserviceID string,
 	displayName *string,
 ) util.JSONResponse {
@@ -751,7 +758,7 @@ type availableResponse struct {
 // RegisterAvailable checks if the username is already taken or invalid.
 func RegisterAvailable(
 	req *http.Request,
-	accountDB *accounts.Database,
+	accountDB registerAccountsData,
 ) util.JSONResponse {
 	username := req.URL.Query().Get("username")
 
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/threepid.go b/src/github.com/matrix-org/dendrite/clientapi/routing/threepid.go
index dd04b1edd..b4c12eb38 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/threepid.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/threepid.go
@@ -15,6 +15,7 @@
 package routing
 
 import (
+	"context"
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
@@ -23,11 +24,18 @@ import (
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/threepid"
 	"github.com/matrix-org/dendrite/common/config"
-
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 )
 
+// interface to accounts database layer
+type threepidAccountsData interface {
+	GetLocalpartForThreePID(context.Context, string, string) (string, error)
+	SaveThreePIDAssociation(context.Context, string, string, string) error
+	GetThreePIDsForLocalpart(context.Context, string) ([]authtypes.ThreePID, error)
+	RemoveThreePIDAssociation(context.Context, string, string) error
+}
+
 type reqTokenResponse struct {
 	SID string `json:"sid"`
 }
@@ -39,7 +47,7 @@ type threePIDsResponse struct {
 // RequestEmailToken implements:
 //     POST /account/3pid/email/requestToken
 //     POST /register/email/requestToken
-func RequestEmailToken(req *http.Request, accountDB *accounts.Database, cfg config.Dendrite) util.JSONResponse {
+func RequestEmailToken(req *http.Request, accountDB threepidAccountsData, cfg config.Dendrite) util.JSONResponse {
 	var body threepid.EmailAssociationRequest
 	if reqErr := httputil.UnmarshalJSONRequest(req, &body); reqErr != nil {
 		return *reqErr
@@ -82,7 +90,7 @@ func RequestEmailToken(req *http.Request, accountDB *accounts.Database, cfg conf
 
 // CheckAndSave3PIDAssociation implements POST /account/3pid
 func CheckAndSave3PIDAssociation(
-	req *http.Request, accountDB *accounts.Database, device *authtypes.Device,
+	req *http.Request, accountDB threepidAccountsData, device *authtypes.Device,
 	cfg config.Dendrite,
 ) util.JSONResponse {
 	var body threepid.EmailAssociationCheckRequest
@@ -142,7 +150,7 @@ func CheckAndSave3PIDAssociation(
 
 // GetAssociated3PIDs implements GET /account/3pid
 func GetAssociated3PIDs(
-	req *http.Request, accountDB *accounts.Database, device *authtypes.Device,
+	req *http.Request, accountDB threepidAccountsData, device *authtypes.Device,
 ) util.JSONResponse {
 	localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
 	if err != nil {
@@ -161,7 +169,7 @@ func GetAssociated3PIDs(
 }
 
 // Forget3PID implements POST /account/3pid/delete
-func Forget3PID(req *http.Request, accountDB *accounts.Database) util.JSONResponse {
+func Forget3PID(req *http.Request, accountDB threepidAccountsData) util.JSONResponse {
 	var body authtypes.ThreePID
 	if reqErr := httputil.UnmarshalJSONRequest(req, &body); reqErr != nil {
 		return *reqErr
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/voip.go b/src/github.com/matrix-org/dendrite/clientapi/routing/voip.go
index 1a2a87527..2f91ad575 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/voip.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/voip.go
@@ -15,12 +15,11 @@
 package routing
 
 import (
-	"net/http"
-
 	"crypto/hmac"
 	"crypto/sha1"
 	"encoding/base64"
 	"fmt"
+	"net/http"
 	"time"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
diff --git a/src/github.com/matrix-org/dendrite/clientapi/threepid/invites.go b/src/github.com/matrix-org/dendrite/clientapi/threepid/invites.go
index 84ba27641..cd334bea7 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/threepid/invites.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/threepid/invites.go
@@ -25,7 +25,6 @@ import (
 	"time"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
-	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/clientapi/producers"
 	"github.com/matrix-org/dendrite/common"
 	"github.com/matrix-org/dendrite/common/config"
@@ -33,6 +32,10 @@ import (
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
+type invitesAccountsData interface {
+	GetProfileByLocalpart(context.Context, string) (*authtypes.Profile, error)
+}
+
 // MembershipRequest represents the body of an incoming POST request
 // on /rooms/{roomID}/(join|kick|ban|unban|leave|invite)
 type MembershipRequest struct {
@@ -87,7 +90,7 @@ var (
 func CheckAndProcessInvite(
 	ctx context.Context,
 	device *authtypes.Device, body *MembershipRequest, cfg config.Dendrite,
-	queryAPI api.RoomserverQueryAPI, db *accounts.Database,
+	queryAPI api.RoomserverQueryAPI, db invitesAccountsData,
 	producer *producers.RoomserverProducer, membership string, roomID string,
 ) (inviteStoredOnIDServer bool, err error) {
 	if membership != "invite" || (body.Address == "" && body.IDServer == "" && body.Medium == "") {
@@ -134,7 +137,7 @@ func CheckAndProcessInvite(
 // Returns an error if a check or a request failed.
 func queryIDServer(
 	ctx context.Context,
-	db *accounts.Database, cfg config.Dendrite, device *authtypes.Device,
+	db invitesAccountsData, cfg config.Dendrite, device *authtypes.Device,
 	body *MembershipRequest, roomID string,
 ) (lookupRes *idServerLookupResponse, storeInviteRes *idServerStoreInviteResponse, err error) {
 	if err = isTrusted(body.IDServer, cfg); err != nil {
@@ -203,7 +206,7 @@ func queryIDServerLookup(ctx context.Context, body *MembershipRequest) (*idServe
 // Returns an error if the request failed to send or if the response couldn't be parsed.
 func queryIDServerStoreInvite(
 	ctx context.Context,
-	db *accounts.Database, cfg config.Dendrite, device *authtypes.Device,
+	db invitesAccountsData, cfg config.Dendrite, device *authtypes.Device,
 	body *MembershipRequest, roomID string,
 ) (*idServerStoreInviteResponse, error) {
 	// Retrieve the sender's profile to get their display name