Downtime security number mainly refers to mobile phone downtime security number, which is a business of mobile communication operators. It refers to the service that mobile operators can reserve numbers for some mobile phone users who don't need a mobile phone number temporarily but want to keep it, as long as they pay a certain fee every month.
Mobile operators in different places provide different mobile phone number protection services according to different local conditions. In some places, users under most types of services cannot enjoy number protection. In some places, operators do not provide number protection. Some local operators only provide this service to users of post-paid brands, and the cost of this service is different. It is best to consult the business hall of the local operator.
As for recovery, you can bring your ID card to the operator's business hall for recovery, and some can call the operator's service phone directly to recover.