DialNext

Tag: SMS Compliance

  • What Is Carrier Filtering in Messaging?

    What Is Carrier Filtering in Messaging?

    Carrier Filtering is the process mobile carriers use to identify, review, and block messages that may violate messaging rules or appear suspicious. It helps protect users from spam, fraud, phishing, and unwanted text messages.

    Businesses that send SMS messages should understand how Carrier Filtering works because it can affect message delivery and customer communication.

    Why Does Carrier Filtering Happen?

    Mobile carriers process billions of messages every day. To protect recipients, carriers analyze messaging traffic and identify content that may be unwanted or harmful.

    Filtering systems help detect:

    • Spam messages
    • Fraud attempts
    • Phishing links
    • Unapproved marketing campaigns
    • High-risk message patterns
    • Policy violations

    Additionally, carriers use filtering systems to maintain trust across messaging networks.

    How Does Carrier Filtering Work?

    Carrier Filtering uses a combination of automated systems, compliance checks, and network rules to evaluate messages.

    Carriers may review several factors, including:

    • Message content
    • Sender reputation
    • Sending patterns
    • Message volume
    • Links included in messages
    • Recipient complaints
    • Registration status

    If a message triggers filtering rules, the carrier may block it before it reaches the recipient.

    Common Reasons Messages Get Filtered

    Messages can be filtered for many reasons.

    Common causes include:

    Missing Registration Requirements

    Some regions require businesses to register before sending application-to-person (A2P) messages.

    For example, businesses sending SMS messages to users in the United States often need approved A2P 10DLC registration.

    Suspicious Message Content

    Carriers may block messages containing:

    • Misleading information
    • Unclear sender identity
    • Suspicious links
    • Excessive capitalization
    • Unusual formatting

    Therefore, businesses should write clear and transparent messages.

    Public URL Shorteners

    Many carriers discourage public URL shorteners because bad actors frequently use them to hide unsafe destinations.

    Instead, use branded links whenever possible.

    Missing Opt-In Consent

    Recipients should agree to receive messages before a business contacts them.

    A clear opt-in process improves compliance and reduces filtering risk.

    High Complaint Rates

    If many recipients report messages as spam, carriers may reduce trust in future messages from the sender.

    Sending relevant messages only to interested users helps maintain a positive reputation.

    How to Reduce Carrier Filtering

    Although filtering decisions depend on carriers, businesses can follow best practices to improve SMS deliverability.

    We recommend:

    • Register required messaging campaigns
    • Collect proper customer consent
    • Clearly identify your business
    • Avoid misleading content
    • Use branded links
    • Provide opt-out instructions
    • Keep contact lists updated
    • Avoid sending unwanted messages

    Following these practices improves message reliability and customer trust.

    Carrier Filtering and A2P 10DLC

    A2P 10DLC registration helps carriers understand who is sending messages and why messages are being sent.

    Approved registration does not guarantee every SMS will be delivered. However, it helps establish sender legitimacy and reduces the chance of unnecessary filtering.

    Businesses should still follow messaging policies after approval.

    Does Carrier Filtering Mean My Message Failed?

    Not always.

    Some carriers provide filtering errors when a message is blocked, while others may silently filter messages based on their internal systems.

    Delivery behavior depends on:

    • Destination carrier
    • Country regulations
    • Sender reputation
    • Message content
    • Compliance requirements

    Does DialNext Prevent Carrier Filtering?

    DialNext helps businesses send reliable SMS messages by supporting proper messaging practices and compliance workflows.

    However, final delivery decisions are controlled by mobile carriers.

    To improve delivery rates, always follow carrier guidelines, maintain customer consent, and send relevant messages.

    Frequently Asked Questions

    Can Carrier Filtering Be Removed?

    No. Carrier filtering exists to protect users and messaging networks. Following best practices reduces the likelihood of legitimate messages being blocked.

    Why Are My SMS Messages Being Blocked?

    Messages may be blocked due to compliance issues, suspicious content, missing registration, or carrier filtering rules.

    Does A2P 10DLC Stop Carrier Filtering?

    No. A2P 10DLC improves sender verification but does not guarantee delivery of every message.

    Do All Carriers Use the Same Filtering Rules?

    No. Each carrier manages its own filtering systems, which means delivery behavior can vary between networks.

    Related Articles

    Additional Resources

    Learn more about messaging guidelines:

    https://www.ctia.org

    Need Help?

    If you have questions about SMS delivery, carrier filtering, or messaging compliance, contact us at help@dialnext.io.

  • A2P 10DLC Registration Guide

    A2P 10DLC Registration Guide

    If your business sends SMS or MMS messages to US phone numbers using local 10-digit phone numbers, you must complete A2P 10DLC registration before sending messages.

    Without an approved registration, carriers may block your messages or limit delivery.

    What is A2P 10DLC?

    A2P 10DLC stands for Application-to-Person 10-Digit Long Code.

    It is the registration framework used by US mobile carriers for business messaging sent through local 10-digit phone numbers.

    The goal is to improve message deliverability, reduce spam, and help carriers verify who is sending messages.

    Who Needs A2P 10DLC Registration?

    You need A2P 10DLC registration if:

    • You send SMS or MMS messages to US phone numbers.
    • You use local US long code numbers.
    • You send business, support, notification, marketing, or transactional messages.

    If you do not send messages to US phone numbers, no action is required.

    How A2P 10DLC Registration Works

    There are two required steps:

    1. Brand Registration

    Brand registration identifies your business.

    Information commonly required includes:

    • Legal business name
    • Business address
    • Tax ID or EIN
    • Business website
    • Company type

    2. Campaign Registration

    Campaign registration identifies the type of messages you send.

    Examples include:

    • Customer care
    • Appointment reminders
    • Account notifications
    • Marketing messages
    • Two-factor authentication

    Each messaging use case must match the campaign you register.

    Information Required for Registration

    Before starting registration, prepare:

    • Legal business name
    • Tax ID or EIN
    • Business website
    • Business address
    • Contact information
    • Sample SMS messages
    • Opt-in process details
    • Privacy Policy URL
    • Terms of Service URL

    Common Reasons for Rejection

    Campaigns are commonly rejected when:

    • Business information does not match official records.
    • Sample messages do not match the declared use case.
    • The website is incomplete or unavailable.
    • Consumer consent is not clearly documented.
    • Privacy Policy or Terms of Service pages are missing.
    • Opt-in and opt-out instructions are unclear.

    Best Practices

    To improve approval rates:

    • Use your legal business name exactly as registered.
    • Make sure your website is publicly accessible.
    • Clearly explain how users consent to receive messages.
    • Include STOP instructions in your messaging program.
    • Maintain Privacy Policy and Terms of Service pages.
    • Ensure sample messages accurately represent your use case.

    Frequently Asked Questions

    Do I need new phone numbers?

    No. Existing US local numbers can usually be associated with an approved campaign.

    Does A2P 10DLC affect WhatsApp?

    No. A2P 10DLC only applies to carrier-based SMS and MMS messaging.

    Does A2P 10DLC apply outside the United States?

    A2P 10DLC primarily applies to messaging sent to US recipients using US local numbers.

    What happens if I don’t register?

    Messages may be blocked, filtered, or experience reduced deliverability.

    Need Help?

    If you need assistance with A2P 10DLC registration, contact help@dialnext.io.

    Related Articles

    Additional Resources

    For the latest carrier registration requirements, review The Campaign Registry .

    You can also review messaging best practices from CTIA .