Legal analysis: it is reasonable to recover the historical arrears automatically written off by mobile. Because the premise of automatic cancellation is that the mobile phone number is overdue for a long time and the system automatically cancels, the parties do have debts in the business hall. Moreover, the fee owed by that number will always be hung on the ID card used by the client to open an account, which will affect other numbers of the ID card. The reason for the long interval is that it takes some time to clean up such accounts.

Legal basis: Article 22 of People's Republic of China (PRC) Telecommunication Regulations shall be settled and apportioned in accordance with the relevant provisions of the state, and fees shall not be charged beyond the prescribed standards.