Summary
Cleaning SMS phone number lists involves a multi-faceted approach focused on improving deliverability, reducing costs, ensuring compliance, and maximizing engagement. Key methods include: validating numbers at the point of entry; regularly removing unsubscribed, inactive, or duplicate numbers; correcting typos; using HLR lookups and third-party validation services to verify number status. Tools like Twilio's Verify API, Vonage's Number Insight API, and MessageBird's platform tools provide real-time validation and insights. Maintaining explicit consent, respecting opt-out requests, and adhering to SMS regulations are critical for compliance. Some experts recommend seeking legal advice before sending SMS/MMS messages and considering services like Black List Alliance. Industry-standard practices include SMS verification upon acquisition. Regularly auditing consent records is essential.
Key findings
- Multi-faceted Approach: Cleaning SMS lists requires a combination of proactive and reactive methods.
- Real-Time Validation: Validating numbers at the point of entry prevents bad data from entering the list.
- API Integration: APIs from providers like Twilio, Vonage, and MessageBird offer automated validation.
- Compliance is Key: Adhering to SMS regulations and managing consent are crucial.
- Regular Maintenance: Regularly removing inactive subscribers and auditing consent are essential for list hygiene.
Key considerations
- Tool Selection: Evaluate different validation services and APIs to find the best fit for your needs.
- Cost-Benefit Analysis: Weigh the costs of cleaning services against the benefits of improved deliverability and reduced expenses.
- Legal Advice: Consider seeking legal advice regarding SMS/MMS messaging to ensure compliance.
- Integration Complexity: Consider the technical complexity of integrating APIs for real-time validation.
- Data Security: Ensure data security when using third-party services to validate phone numbers.
What email marketers say
14 marketer opinions
Cleaning SMS phone number lists involves various methods to ensure messages reach valid recipients, improve deliverability, reduce costs, and maintain regulatory compliance. Key methods include real-time validation at entry, removing unsubscribed or inactive numbers, correcting typos, using HLR lookups to verify number status, and employing third-party validation services. Obtaining explicit consent and respecting opt-out requests are also essential. Some services offer features like 7-digit validation or HLR lookups to improve data quality. While specific cleaning tools may not exist, industry-standard practices involve verifying numbers during acquisition via SMS or using services like Twilio's Verify API.
Key opinions
- Validation Methods: Various validation methods exist, including real-time validation at entry, SMS verification, HLR lookups, and third-party services.
- List Maintenance: Regularly removing unsubscribed, inactive, or duplicate numbers is crucial for list hygiene.
- Compliance: Obtaining explicit consent, respecting opt-out requests, and adhering to SMS regulations are essential.
- Data Accuracy: Correcting typos and formatting errors improves deliverability and prevents messages from reaching the wrong numbers.
- Industry Practices: Verifying numbers upon acquisition via SMS is an industry-standard practice.
Key considerations
- Consent and Opt-Out: Always obtain explicit consent before sending SMS messages and provide a clear opt-out mechanism.
- Validation Service Selection: Choose a validation service that meets your specific needs, considering factors like data quality, features, and pricing.
- Regulatory Compliance: Stay up-to-date with SMS regulations in your region and ensure your practices comply.
- List Segmentation: Consider segmenting your list based on engagement and activity to improve deliverability and engagement rates.
- Cost-Benefit Analysis: Evaluate the costs of list cleaning services against the potential benefits of improved deliverability and reduced expenses on invalid numbers.
Marketer view
Marketer from Email Geeks shares that some SMS providers can do HLR lookups before sending the SMS to check if the number is valid on the network.
26 Jun 2024 - Email Geeks
Marketer view
Email marketer from Reddit suggests using list cleaning services to validate phone numbers. These services will automatically clean up and remove phone numbers that are not active or that are disconnected. They also remove duplicates.
26 May 2024 - Reddit
What the experts say
1 expert opinions
Maintaining SMS compliance is vital for effective list management. This includes obtaining explicit consent, avoiding prohibited content, providing clear opt-out options, regularly removing inactive numbers, and auditing consent records. These practices maintain list hygiene and ensure adherence to SMS regulations.
Key opinions
- SMS Compliance: Compliance encompasses consent, content restrictions, and opt-out mechanisms.
- List Hygiene: Regularly removing inactive numbers improves list quality.
- Consent Auditing: Auditing consent records ensures ongoing compliance.
Key considerations
- Consent Management: Implement robust consent management processes.
- Opt-Out Clarity: Ensure opt-out instructions are clear and accessible.
- Regular Audits: Schedule regular audits of consent records and list hygiene practices.
Expert view
Expert from Word to the Wise stresses the importance of SMS compliance, which includes obtaining consent, avoiding prohibited content, and providing clear opt-out mechanisms. Regularly reviewing and removing inactive numbers, as well as auditing consent records, will help maintain list hygiene and ensure compliance with SMS regulations.
24 Dec 2021 - Word to the Wise
What the documentation says
3 technical articles
Twilio, Vonage, and MessageBird offer APIs and tools for SMS list cleaning. Twilio's Verify API validates numbers by sending a verification code. Vonage's Number Insight API provides real-time phone number information, including validity and carrier details, for identifying invalid numbers. MessageBird offers platform tools to check number validity before sending messages. All three solutions aim to reduce costs and improve deliverability by removing invalid or inactive numbers from SMS campaigns.
Key findings
- API Validation: APIs like Twilio's Verify and Vonage's Number Insight can validate phone numbers in real-time.
- Cost Reduction: Using these tools reduces costs associated with sending messages to invalid numbers.
- Improved Deliverability: Validating numbers enhances overall SMS campaign efficiency and deliverability.
- Number Insight: Vonage's Number Insight API provides additional phone number details like carrier information.
Key considerations
- Integration Effort: Integrating these APIs requires development effort and technical expertise.
- Pricing Models: Evaluate the pricing models of each service to determine the most cost-effective solution for your needs.
- Feature Set: Consider the specific features offered by each API and choose the one that best aligns with your requirements.
- Data Security: Ensure data security and privacy when using third-party APIs for phone number validation.
Technical article
Documentation from Twilio explains that their Verify API can validate phone numbers by sending a verification code via SMS. This confirms that the number is active and reachable, reducing the risk of sending messages to invalid or inactive numbers. This can reduce costs and improve deliverability.
30 May 2025 - Twilio
Technical article
Documentation from MessageBird explains that their platform offers tools to check the validity of phone numbers before sending SMS messages. By using these tools, users can reduce costs associated with sending to invalid numbers and improve the overall efficiency of their SMS campaigns. They also advise removing inactive users from your list.
28 Oct 2022 - MessageBird
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