diff --git a/state/device_data_table.go b/state/device_data_table.go
index 1ed3e87..2c5576d 100644
--- a/state/device_data_table.go
+++ b/state/device_data_table.go
@@ -21,7 +21,8 @@ type DeviceDataRow struct {
 }
 
 type DeviceDataTable struct {
-	db *sqlx.DB
+	db              *sqlx.DB
+	deviceListTable *DeviceListTable
 }
 
 func NewDeviceDataTable(db *sqlx.DB) *DeviceDataTable {
@@ -37,7 +38,8 @@ func NewDeviceDataTable(db *sqlx.DB) *DeviceDataTable {
 	ALTER TABLE syncv3_device_data SET (fillfactor = 90);
 	`)
 	return &DeviceDataTable{
-		db: db,
+		db:              db,
+		deviceListTable: NewDeviceListTable(db),
 	}
 }
 
diff --git a/state/device_data_table_test.go b/state/device_data_table_test.go
index d099eda..b4fe6ad 100644
--- a/state/device_data_table_test.go
+++ b/state/device_data_table_test.go
@@ -118,160 +118,6 @@ func TestDeviceDataTableOTKCountAndFallbackKeyTypes(t *testing.T) {
 	assertDeviceData(t, *got, want)
 }
 
-// Tests the DeviceLists field
-func TestDeviceDataTableDeviceList(t *testing.T) {
-	db, close := connectToDB(t)
-	defer close()
-	table := NewDeviceDataTable(db)
-	userID := "@TestDeviceDataTableDeviceList"
-	deviceID := "BOB"
-
-	// these are individual updates from Synapse from /sync v2
-	deltas := []internal.DeviceData{
-		{
-			UserID:   userID,
-			DeviceID: deviceID,
-			DeviceLists: internal.DeviceLists{
-				New: internal.ToDeviceListChangesMap([]string{"alice"}, nil),
-			},
-		},
-		{
-			UserID:   userID,
-			DeviceID: deviceID,
-			DeviceLists: internal.DeviceLists{
-				New: internal.ToDeviceListChangesMap([]string{"💣"}, nil),
-			},
-		},
-	}
-	// apply them
-	for _, dd := range deltas {
-		err := table.Upsert(&dd)
-		assertNoError(t, err)
-	}
-
-	// check we can read-only select. This doesn't modify any fields.
-	for i := 0; i < 3; i++ {
-		got, err := table.Select(userID, deviceID, false)
-		assertNoError(t, err)
-		assertDeviceData(t, *got, internal.DeviceData{
-			UserID:   userID,
-			DeviceID: deviceID,
-			DeviceLists: internal.DeviceLists{
-				Sent: internal.MapStringInt{}, // until we "swap" we don't consume the New entries
-			},
-		})
-	}
-	// now swap-er-roo, which shifts everything from New into Sent.
-	got, err := table.Select(userID, deviceID, true)
-	assertNoError(t, err)
-	assertDeviceData(t, *got, internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			Sent: internal.ToDeviceListChangesMap([]string{"alice", "💣"}, nil),
-		},
-	})
-
-	// this is permanent, read-only views show this too.
-	got, err = table.Select(userID, deviceID, false)
-	assertNoError(t, err)
-	assertDeviceData(t, *got, internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			Sent: internal.ToDeviceListChangesMap([]string{"alice", "💣"}, nil),
-		},
-	})
-
-	// We now expect empty DeviceLists, as we swapped twice.
-	got, err = table.Select(userID, deviceID, true)
-	assertNoError(t, err)
-	assertDeviceData(t, *got, internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			Sent: internal.MapStringInt{},
-		},
-	})
-
-	// get back the original state
-	assertNoError(t, err)
-	for _, dd := range deltas {
-		err = table.Upsert(&dd)
-		assertNoError(t, err)
-	}
-	// Move original state to Sent by swapping
-	got, err = table.Select(userID, deviceID, true)
-	assertNoError(t, err)
-	assertDeviceData(t, *got, internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			Sent: internal.ToDeviceListChangesMap([]string{"alice", "💣"}, nil),
-		},
-	})
-	// Add new entries to New before acknowledging Sent
-	err = table.Upsert(&internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			New: internal.ToDeviceListChangesMap([]string{"💣"}, []string{"charlie"}),
-		},
-	})
-	assertNoError(t, err)
-
-	// Reading without swapping does not move New->Sent, so returns the previous value
-	got, err = table.Select(userID, deviceID, false)
-	assertNoError(t, err)
-	assertDeviceData(t, *got, internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			Sent: internal.ToDeviceListChangesMap([]string{"alice", "💣"}, nil),
-		},
-	})
-
-	// Append even more items to New
-	err = table.Upsert(&internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			New: internal.ToDeviceListChangesMap([]string{"dave"}, []string{"dave"}),
-		},
-	})
-	assertNoError(t, err)
-
-	// Now swap: all the combined items in New go into Sent
-	got, err = table.Select(userID, deviceID, true)
-	assertNoError(t, err)
-	assertDeviceData(t, *got, internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			Sent: internal.ToDeviceListChangesMap([]string{"💣", "dave"}, []string{"charlie", "dave"}),
-		},
-	})
-
-	// Swapping again clears Sent out, and since nothing is in New we get an empty list
-	got, err = table.Select(userID, deviceID, true)
-	assertNoError(t, err)
-	assertDeviceData(t, *got, internal.DeviceData{
-		UserID:   userID,
-		DeviceID: deviceID,
-		DeviceLists: internal.DeviceLists{
-			Sent: internal.MapStringInt{},
-		},
-	})
-
-	// delete everything, no data returned
-	assertNoError(t, table.DeleteDevice(userID, deviceID))
-	got, err = table.Select(userID, deviceID, false)
-	assertNoError(t, err)
-	if got != nil {
-		t.Errorf("wanted no data, got %v", got)
-	}
-}
-
 func TestDeviceDataTableBitset(t *testing.T) {
 	db, close := connectToDB(t)
 	defer close()
diff --git a/state/device_list_table.go b/state/device_list_table.go
new file mode 100644
index 0000000..5baae56
--- /dev/null
+++ b/state/device_list_table.go
@@ -0,0 +1,110 @@
+package state
+
+import (
+	"fmt"
+
+	"github.com/getsentry/sentry-go"
+	"github.com/jmoiron/sqlx"
+	"github.com/matrix-org/sliding-sync/internal"
+	"github.com/matrix-org/sliding-sync/sqlutil"
+)
+
+const (
+	BucketNew  = 1
+	BucketSent = 2
+)
+
+type DeviceListTable struct {
+	db *sqlx.DB
+}
+
+func NewDeviceListTable(db *sqlx.DB) *DeviceListTable {
+	db.MustExec(`
+	CREATE TABLE IF NOT EXISTS syncv3_device_list_updates (
+		user_id TEXT NOT NULL,
+		device_id TEXT NOT NULL,
+		target_user_id TEXT NOT NULL,
+		target_state SMALLINT NOT NULL,
+		bucket SMALLINT NOT NULL,
+		UNIQUE(user_id, device_id, target_user_id, bucket)
+	);
+	-- make an index so selecting all the rows is faster
+	CREATE INDEX IF NOT EXISTS syncv3_device_list_updates_bucket_idx ON syncv3_device_list_updates(user_id, device_id, bucket);
+	-- Set the fillfactor to 90%, to allow for HOT updates (e.g. we only
+	-- change the data, not anything indexed like the id)
+	ALTER TABLE syncv3_device_list_updates SET (fillfactor = 90);
+	`)
+	return &DeviceListTable{
+		db: db,
+	}
+}
+
+// Upsert new device list changes.
+func (t *DeviceListTable) Upsert(userID, deviceID string, deviceListChanges map[string]int) (err error) {
+	err = sqlutil.WithTransaction(t.db, func(txn *sqlx.Tx) error {
+		for targetUserID, targetState := range deviceListChanges {
+			if targetState != internal.DeviceListChanged && targetState != internal.DeviceListLeft {
+				sentry.CaptureException(fmt.Errorf("DeviceListTable.Upsert invalid target_state: %d this is a programming error", targetState))
+				continue
+			}
+			_, err = txn.Exec(
+				`INSERT INTO syncv3_device_list_updates(user_id, device_id, target_user_id, target_state, bucket) VALUES($1,$2,$3,$4,$5)
+			ON CONFLICT (user_id, device_id, target_user_id, bucket) DO UPDATE SET target_state=$4`,
+				userID, deviceID, targetUserID, targetState, BucketNew,
+			)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		sentry.CaptureException(err)
+	}
+	return
+}
+
+// Select device list changes for this client. Returns a map of user_id => change enum.
+func (t *DeviceListTable) Select(userID, deviceID string, swap bool) (result internal.MapStringInt, err error) {
+	err = sqlutil.WithTransaction(t.db, func(txn *sqlx.Tx) error {
+		if !swap {
+			// read only view, just return what we previously sent and don't do anything else.
+			result, err = t.selectDeviceListChangesInBucket(txn, userID, deviceID, BucketSent)
+			return err
+		}
+
+		// delete the now acknowledged 'sent' data
+		_, err = txn.Exec(`DELETE FROM syncv3_device_list_updates WHERE user_id=$1 AND device_id=$2 AND bucket=$3`, userID, deviceID, BucketSent)
+		if err != nil {
+			return err
+		}
+		// grab any 'new' updates
+		result, err = t.selectDeviceListChangesInBucket(txn, userID, deviceID, BucketNew)
+		if err != nil {
+			return err
+		}
+
+		// mark these 'new' updates as 'sent'
+		_, err = txn.Exec(`UPDATE syncv3_device_list_updates SET bucket=$1 WHERE user_id=$2 AND device_id=$3 AND bucket=$4`, BucketSent, userID, deviceID, BucketNew)
+		return err
+	})
+	return
+}
+
+func (t *DeviceListTable) selectDeviceListChangesInBucket(txn *sqlx.Tx, userID, deviceID string, bucket int) (result internal.MapStringInt, err error) {
+	rows, err := txn.Query(`SELECT target_user_id, target_state FROM syncv3_device_list_updates WHERE user_id=$1 AND device_id=$2 AND bucket=$3`, userID, deviceID, bucket)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	result = make(internal.MapStringInt)
+	var targetUserID string
+	var targetState int
+	for rows.Next() {
+		if err := rows.Scan(&targetUserID, &targetState); err != nil {
+			return nil, err
+		}
+		result[targetUserID] = targetState
+	}
+	return result, rows.Err()
+}
diff --git a/state/device_list_table_test.go b/state/device_list_table_test.go
new file mode 100644
index 0000000..79cf843
--- /dev/null
+++ b/state/device_list_table_test.go
@@ -0,0 +1,108 @@
+package state
+
+import (
+	"testing"
+
+	"github.com/matrix-org/sliding-sync/internal"
+)
+
+// Tests the DeviceLists table
+func TestDeviceListTable(t *testing.T) {
+	db, close := connectToDB(t)
+	defer close()
+	table := NewDeviceListTable(db)
+	userID := "@TestDeviceListTable"
+	deviceID := "BOB"
+
+	// these are individual updates from Synapse from /sync v2
+	deltas := []internal.MapStringInt{
+		{
+			"alice": internal.DeviceListChanged,
+		},
+		{
+			"💣": internal.DeviceListChanged,
+		},
+	}
+	// apply them
+	for _, dd := range deltas {
+		err := table.Upsert(userID, deviceID, dd)
+		assertNoError(t, err)
+	}
+
+	// check we can read-only select. This doesn't modify any fields.
+	for i := 0; i < 3; i++ {
+		got, err := table.Select(userID, deviceID, false)
+		assertNoError(t, err)
+		// until we "swap" we don't consume the New entries
+		assertVal(t, "unexpected data on swapless select", got, internal.MapStringInt{})
+	}
+	// now swap-er-roo, which shifts everything from New into Sent.
+	got, err := table.Select(userID, deviceID, true)
+	assertNoError(t, err)
+	assertVal(t, "did not select what was upserted on swap select", got, internal.MapStringInt{
+		"alice": internal.DeviceListChanged,
+		"💣":     internal.DeviceListChanged,
+	})
+
+	// this is permanent, read-only views show this too.
+	got, err = table.Select(userID, deviceID, false)
+	assertNoError(t, err)
+	assertVal(t, "swapless select did not return the same data as before", got, internal.MapStringInt{
+		"alice": internal.DeviceListChanged,
+		"💣":     internal.DeviceListChanged,
+	})
+
+	// We now expect empty DeviceLists, as we swapped twice.
+	got, err = table.Select(userID, deviceID, true)
+	assertNoError(t, err)
+	assertVal(t, "swap select did not return nothing", got, internal.MapStringInt{})
+
+	// get back the original state
+	assertNoError(t, err)
+	for _, dd := range deltas {
+		err = table.Upsert(userID, deviceID, dd)
+		assertNoError(t, err)
+	}
+	// Move original state to Sent by swapping
+	got, err = table.Select(userID, deviceID, true)
+	assertNoError(t, err)
+	assertVal(t, "did not select what was upserted on swap select", got, internal.MapStringInt{
+		"alice": internal.DeviceListChanged,
+		"💣":     internal.DeviceListChanged,
+	})
+	// Add new entries to New before acknowledging Sent
+	err = table.Upsert(userID, deviceID, internal.MapStringInt{
+		"💣":       internal.DeviceListChanged,
+		"charlie": internal.DeviceListLeft,
+	})
+	assertNoError(t, err)
+
+	// Reading without swapping does not move New->Sent, so returns the previous value
+	got, err = table.Select(userID, deviceID, false)
+	assertNoError(t, err)
+	assertVal(t, "swapless select did not return the same data as before", got, internal.MapStringInt{
+		"alice": internal.DeviceListChanged,
+		"💣":     internal.DeviceListChanged,
+	})
+
+	// Append even more items to New
+	err = table.Upsert(userID, deviceID, internal.MapStringInt{
+		"charlie": internal.DeviceListChanged, // we previously said "left" for charlie, so as "changed" is newer, we should see "changed"
+		"dave":    internal.DeviceListLeft,
+	})
+	assertNoError(t, err)
+
+	// Now swap: all the combined items in New go into Sent
+	got, err = table.Select(userID, deviceID, true)
+	assertNoError(t, err)
+	assertVal(t, "swap select did not return combined new items", got, internal.MapStringInt{
+		"💣":       internal.DeviceListChanged,
+		"charlie": internal.DeviceListChanged,
+		"dave":    internal.DeviceListLeft,
+	})
+
+	// Swapping again clears Sent out, and since nothing is in New we get an empty list
+	got, err = table.Select(userID, deviceID, true)
+	assertNoError(t, err)
+	assertVal(t, "swap select did not return combined new items", got, internal.MapStringInt{})
+}