How to Clean and Verify Your Phone Number Lists:
Posted: Sat May 24, 2025 8:56 am
1. Implement Double Opt-in (Preventative Measure):
Strategy: This is the most effective proactive cleaning method. By requiring subscribers to confirm their opt-in via a reply or click, you ensure the number is valid and the user is genuinely interested.
Benefit: Reduces invalid numbers entering your list from the start.
2. Automate Hard Bounce Removal:
Strategy: Hard bounces occur when a message permanently fails to deliver (e.g., number doesn't exist, invalid number). Your SMS marketing platform should automatically identify and remove these numbers from your active list.
Benefit: Prevents repeatedly sending to dead ends, which is a major red flag for carriers.
3. Monitor and Manage Soft Bounces:
Strategy: Soft bounces are temporary delivery failures (e.g., full inbox, temporary network issue). While not immediately removed, consistent soft bounces from the same number over time indicate a persistent issue.
Benefit: Set a threshold (e.g., 3-5 consecutive soft bounces over a south africa phone number list month, or persistent soft bounces over 3-6 months) after which the number should be removed or placed on a suppression list.
4. Implement an Inactivity Management Process:
Strategy: Identify subscribers who haven't engaged with your SMS messages (no opens, clicks, or replies) for a defined period (e.g., 6-12 months).
Benefit:
Re-engagement Campaign: Send a targeted SMS to these inactive users, offering a compelling incentive to re-engage or explicitly asking if they still wish to receive messages ("Reply YES to stay subscribed!").
Suppression: If they don't respond, move them to a suppression list, rather than outright deletion. This ensures you don't accidentally re-add them while not sending them unwanted messages.
5. Utilize Phone Number Verification Services:
Strategy: For large lists, or lists acquired through various means (e.g., legacy data, large lead gen campaigns), use third-party phone number verification services. These services check numbers against carrier databases to confirm their validity and active status.
Benefit: Provides a bulk validation, identifying invalid numbers before you even send a single message, saving costs and protecting sender reputation.
Strategy: This is the most effective proactive cleaning method. By requiring subscribers to confirm their opt-in via a reply or click, you ensure the number is valid and the user is genuinely interested.
Benefit: Reduces invalid numbers entering your list from the start.
2. Automate Hard Bounce Removal:
Strategy: Hard bounces occur when a message permanently fails to deliver (e.g., number doesn't exist, invalid number). Your SMS marketing platform should automatically identify and remove these numbers from your active list.
Benefit: Prevents repeatedly sending to dead ends, which is a major red flag for carriers.
3. Monitor and Manage Soft Bounces:
Strategy: Soft bounces are temporary delivery failures (e.g., full inbox, temporary network issue). While not immediately removed, consistent soft bounces from the same number over time indicate a persistent issue.
Benefit: Set a threshold (e.g., 3-5 consecutive soft bounces over a south africa phone number list month, or persistent soft bounces over 3-6 months) after which the number should be removed or placed on a suppression list.
4. Implement an Inactivity Management Process:
Strategy: Identify subscribers who haven't engaged with your SMS messages (no opens, clicks, or replies) for a defined period (e.g., 6-12 months).
Benefit:
Re-engagement Campaign: Send a targeted SMS to these inactive users, offering a compelling incentive to re-engage or explicitly asking if they still wish to receive messages ("Reply YES to stay subscribed!").
Suppression: If they don't respond, move them to a suppression list, rather than outright deletion. This ensures you don't accidentally re-add them while not sending them unwanted messages.
5. Utilize Phone Number Verification Services:
Strategy: For large lists, or lists acquired through various means (e.g., legacy data, large lead gen campaigns), use third-party phone number verification services. These services check numbers against carrier databases to confirm their validity and active status.
Benefit: Provides a bulk validation, identifying invalid numbers before you even send a single message, saving costs and protecting sender reputation.