This article describes best practices that should be followed while dealing with deactivated phone numbers, including how to find out if a phone number has been deactivated and how to deal with deactivated phone numbers. 

What is a deactivated phone number?

A phone number is deactivated on one wireless carrier when a mobile subscriber either terminates their service with that carrier or ports their number to a different wireless carrier. Eventually, each deactivated numbers get recycled, and gets assigned to new subscribers.

Why is it important to keep track of deactivated phone numbers?

When a deactivated number is assigned to a new subscriber, it means that that phone number is no longer associated with the end user who opted in to your messaging campaign. 

How do I track deactivated phone numbers on my network?

Wireless carriers in Canada and the United States routinely publish Deactivation Reports that contain a list of all the deactivated phone numbers within their networks. These reports help message senders keep their programs in compliance.

What happens if I don’t keep a list of healthy subscribers?.

Maintaining a healthy list of subscribers who have opted in to receive your messages is crucial in both US and Canada. Sending messages to end users who have not opted into your programs can result in complaints, following which your messages could be marked as spam. Additionally, carriers can filter out your messages, and in worst-case scenarios, the Federal Communications Commission (FCC) can issue fines.

Sending messages to deactivated phone numbers still incurs costs to you, so keeping your subscriber lists clean can save you charges on unnecessary messages.