Carrier blockage may occur anytime for various reasons carriers do not disclose. When it occurs, carriers block specific SMS, causing them not to be delivered to your leads.
Note: Carriers do not usually block your account or the number/s used for a campaign. The blockage influences only SMS sent.
There are some general recommendations that should help avoid high blockage and keep the block rate at its minimum:
- Make sure you use fresh, good-quality lists properly skip-traced, and make sure you verify them. If you ever reuse old (uploaded more than three weeks ago), previously verified lists, please make sure to re-verify them again before sending a campaign to ensure any numbers that went invalid/opted out since the time the list was last verified are scrubbed.
- Ensure the campaigns you send align with the campaign description provided when registering your brand with A2P 10DLC.
- Use varying message templates. Keep your message templates clear and informative to avoid flagging them as spam.
- Introduce yourself and include your Company name in your initial campaign messages. Some carriers may find your traffic incompliant and filter it if your messages lack a proper sender identification, so it's always a good idea to include your brand name in the initial campaign templates.
- Include Opt-Out language in your initial campaign messages. The opt-out text is added to your initial message templates by default, and we do not recommend disabling it as it may greatly impact your delivery rate. If you are an Elite user, you can remove it from your templates, but we would recommend keeping it in the initial templates and removing it from the follow-up templates only.
- Keep no more than ONE approved number per the area code you market to. This usually produces better deliverability and a lower block rate than if you used more than one number with the same area code.
- Do not change your approved numbers often. The numbers you purchased and got approved with carriers are linked to your registration, so it's recommended to stick to them. Using the same numbers for a long time helps build your trust score with carriers and improve deliverability.