Dunning companies are legal as long as they are established according to law. Dunning companies must abide by the law and discipline when collecting debts, and must not use violence to collect debts. The statutory limitation of action for creditor's rights and debts in China is three years, and the limitation of action will be recalculated every time the dunning is made. However, if there is evidence to prove the act of dunning, the limitation of action may be interrupted.