diff --git a/internal/adapter/out/redis/quota.go b/internal/adapter/out/redis/quota.go
index 35e51c0..8c38718 100644
--- a/internal/adapter/out/redis/quota.go
+++ b/internal/adapter/out/redis/quota.go
@@ -31,10 +31,36 @@ func (q *RoomQuota) TakePick(ctx context.Context, roomID string, burst int, refi
 }
 
 func (q *RoomQuota) take(ctx context.Context, roomID, bucket, what string, burst int, refill time.Duration) (time.Duration, error) {
-	res, err := q.limiter.Allow(ctx, "room:"+roomID+":"+bucket, redis_rate.Limit{Rate: 1, Burst: burst, Period: refill})
+	wait, err := take(ctx, q.limiter, "room:"+roomID+":"+bucket, burst, refill)
 	if err != nil {
 		return 0, fmt.Errorf("取房间 %s 的%s额度：%w", roomID, what, err)
 	}
+	return wait, nil
+}
+
+var _ port.AccountQuota = (*AccountQuota)(nil)
+
+type AccountQuota struct {
+	limiter *redis_rate.Limiter
+}
+
+func NewAccountQuota(client *goredis.Client) *AccountQuota {
+	return &AccountQuota{limiter: redis_rate.NewLimiter(client)}
+}
+
+func (q *AccountQuota) Take(ctx context.Context, key string, burst int, refill time.Duration) (time.Duration, error) {
+	wait, err := take(ctx, q.limiter, "account:"+key, burst, refill)
+	if err != nil {
+		return 0, fmt.Errorf("取 %s 的额度：%w", key, err)
+	}
+	return wait, nil
+}
+
+func take(ctx context.Context, limiter *redis_rate.Limiter, key string, burst int, refill time.Duration) (time.Duration, error) {
+	res, err := limiter.Allow(ctx, key, redis_rate.Limit{Rate: 1, Burst: burst, Period: refill})
+	if err != nil {
+		return 0, err
+	}
 	if res.Allowed > 0 {
 		return 0, nil
 	}
diff --git a/internal/adapter/out/redis/quota_test.go b/internal/adapter/out/redis/quota_test.go
index f9281a7..f517cef 100644
--- a/internal/adapter/out/redis/quota_test.go
+++ b/internal/adapter/out/redis/quota_test.go
@@ -43,3 +43,26 @@ func TestTakePick(t *testing.T) {
 		t.Errorf("另一个房间 = %v, %v，点歌额度按房间计算", wait, err)
 	}
 }
+
+func TestAccountQuota(t *testing.T) {
+	client := newClient(t)
+	quota := NewAccountQuota(client)
+	for i := range 2 {
+		if wait, err := quota.Take(t.Context(), "login:ip:203.0.113.7", 2, time.Minute); err != nil || wait != 0 {
+			t.Fatalf("第 %d 次 = %v, %v，突发额度之内应直接取到", i+1, wait, err)
+		}
+	}
+	wait, err := quota.Take(t.Context(), "login:ip:203.0.113.7", 2, time.Minute)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if wait < 59*time.Second || wait > time.Minute {
+		t.Errorf("额度用完后要等 %v，期望约 1 分钟", wait)
+	}
+	if wait, err := quota.Take(t.Context(), "login:user:alice", 2, time.Minute); err != nil || wait != 0 {
+		t.Errorf("另一个键 = %v, %v，额度按键计算", wait, err)
+	}
+	if wait, err := NewRoomQuota(client).TakeSearch(t.Context(), "login:ip:203.0.113.7", 1, time.Minute); err != nil || wait != 0 {
+		t.Errorf("房间额度 = %v, %v，账号额度的键不能与房间额度的键重合", wait, err)
+	}
+}
diff --git a/internal/app/port/quota.go b/internal/app/port/quota.go
index 124f52f..a18f1ea 100644
--- a/internal/app/port/quota.go
+++ b/internal/app/port/quota.go
@@ -13,3 +13,9 @@ type RoomQuota interface {
 	// 与 TakeSearch 相同，取的是点歌额度。
 	TakePick(ctx context.Context, roomID string, burst int, refill time.Duration) (time.Duration, error)
 }
+
+// 注册、登录、修改密码的额度，按调用方拼出的键计数，所有实例共用。
+type AccountQuota interface {
+	// 与 RoomQuota.TakeSearch 相同：取到时返回 0，额度用完时返回还要等待的时长。
+	Take(ctx context.Context, key string, burst int, refill time.Duration) (time.Duration, error)
+}