How to Prevent SMS Filtering by Carriers: Error 30007

What is Error 30007 – Carrier Filtering?

30007 is a carrier-side error that indicates your message was filtered due to content, sender identity, or compliance reasons.

This happens when a message:

Violates a carrier’s messaging policy.
Appears similar to spam or illegal traffic.
Is missing required compliance elements, like opt-in consent or sender identification.

These filters are enforced to protect consumers, comply with national regulations and maintain platform trust.

If you want more information on message filtering, please check out this article: How Does Message Filtering Work?

How to Prevent Messages from Being Filtered

Below are structured guidelines based on carrier requirements, Clinic Convert policies, and industry best practices.

Only message users who’ve explicitly opted in.
Your message must identify the sender and include opt-out instructions.
You must include STOP language at least once every 30 days if you message the same contact regularly.
Avoid creative variations like “Reply 2 to unsubscribe” – these are non-compliant and will be filtered.
Reconfirm opt-in every 18 months to avoid accidental messaging of recycled numbers.
Monitor opt-out rates and complaint spikes, carriers will begin filtering traffic that shows abuse patterns.

2. Use Case & Sender Selection

Avoid forbidden use cases, such as payday loans, debt relief, cannabis, etc.
Do not “snowshoe” across multiple numbers to evade filtering – use numbers based on geography or business units only.
Use pre-registered short codes or Alphanumeric Sender IDs where required, especially for countries like France.
Refer to SMS Guidelines by Country for local rules.

3. Message Content & Formatting

Avoid public URL shorteners (like Bitly, TinyURL). Use branded domains like (yourbusiness.com/offer).
Never use obfuscated links or suspicious redirects.
Use clear, well-written language and avoid,
1. Emojis, excessive punctuation, or CAPS.
2. Misspellings or poor grammar.
Do not send illegal or misleading content, or anything listed in the Forbidden Categories.

4. Opt-Out & Compliance Requirements

Your SMS must:

Contain STOP instructions (at least monthly).
Clearly name the sender.
Be sent only to users who gave explicit permission.

5. Monitoring & DND Handling

Process DND (Do Not Disturb) requests daily – deactivated numbers are no longer valid recipients.
A message triggering 30007 can mark a contact as DND automatically.

Best Practices

Use custom or branded short URLs linked to your business domain.
Limit redirects to no more than one, and avoid cloaking link destinations.
When possible, include the full URL to boost transparency (even if it takes extra characters).
Improving your URL practices can prevent filtering and ensure your messages reach their audience.
If sending links through sms only use links provided in their A2P.
Links will need to have that specific domain address when they send sms or else it could be filtered.

Think You’re Being Filtered by Mistake?

If your messages meet all compliance criteria but are still blocked:

Gather 3+ contact examples from the past 7 days that show error 30007.
Share the links with our Support team for review.

Frequently Asked Questions

Q: Why does message filtering vary between carriers?

Each carrier uses different filtering logic and algorithms. A message blocked by one carrier (e.g., Verizon) might be delivered by another (e.g., AT&T), depending on the content, volume, and sender history.

Q: What if I’m messaging international numbers?

Each country has different SMS rules. Some require specific sender types (e.g., short codes or alpha IDs), and others restrict certain industries.

Q: How do I know if a contact was marked DND because of 30007?

You can check their conversation status, error logs, and delivery error codes. If they are in DND, and messages were previously filtered, it's likely related.

Q: Will repeated 30007 errors block my number permanently?

It can lead to DND status, restriction, or even number deactivation if unresolved.

Q: How can I test if my messages will be filtered?

There’s no test tool, but following best practices significantly reduces the risk.

Q: Can I use emojis or shortened links?

Best to avoid both. Use only branded URLs and standard language formatting.