Skip to main content

SMS Error Codes

Outlining the statuses for messages sent by Salesmsg

O
Written by Operations Manager

SMS Error Codes

If you send an SMS through Salesmsg and see an error, this guide will help you:

  • Understand what the error means

  • Know what you can try to fix it

  • Learn how to view the error code directly in your interface

🏆 #1 Recommendation

Enable PhoneCheckr to lookup your contact phone numbers to ensure that you send texts to valid numbers that can receive SMS text messages.

How to View the Error Code

  1. In your Salesmsg Conversations page, and locate the message that shows a red “×” (indicating failure).

  2. Hover your mouse cursor over the red “×” icon (or tap/long-press on mobile).

  3. A small tooltip or popup will display the error code (e.g. “30003”) and often a short description.

This helps you quickly see which error you're dealing with and refer to this guide for next steps.

2000 - 2999 Errors

Code

Description

What’s Happening

What to Try

21266

“To” and “From” numbers can’t be the same

You tried sending from a number to itself

Use different numbers; don’t set “to” and “from” as the same value

21211

Invalid “To” number

Wrong formatting or invalid phone number

Check number format, use a valid mobile number

21408

SMS permission not enabled for region

Region isn’t enabled in your account.


Currently, the default regions available in Salesmsg are:

  • U.S. 🇺🇸

  • Canada 🇨🇦

  • Great Britain🇬🇧

  • Australia🇦🇺

Look at Extending international texting via your General settings. (Additional rates apply.)

21606

“From” number is not SMS-capable.

You can only send SMS messages from a phone number or short code provided by or ported to Salesmsg, and that phone number must be SMS-capable.

For short codes, the From number must be in the same country as the To number.

The sending number isn’t enabled or valid

Use a Salesmsg SMS-enabled number and confirm it’s listed as such.

If you are sending from a short code, verify that the country you are sending to matches the country of the short code.

21610

Recipient has unsubscribed

The person previously replied “STOP”

  • Remove the number so that messages are no longer attempted

  • Or: ask them to text the original sender: “START”, to re-opt in.

21612

Invalid “To” / “From” combination

Most likely that Salesmsg does not yet have service with the carrier you are trying to reach.

Check number formats, use supported carriers

21614

“To” isn’t a mobile number

You tried sending to a landline or invalid number

  • Use mobile numbers only

  • To confirm the number you are sending to is not a landline, look at enabling PhoneCheckr via your General settings.
    (Additional rates apply.)

21621

Your number does not support MMS

You tried to send a message with an image or attachment from a number that is only SMS-capable (this is common with toll-free, short code, and non-US/Canada numbers).

  • Remove the attachment and send text only

  • Or send from an MMS-capable Salesmsg number

  • Share the file as a link in the message body instead

3000 - 3999 Errors

Code

Description

What’s Happening

What to Try

30001

Exceeded the permitted messages per second for the number type

Messages were submitted faster than your number type is allowed to send. Every number type has its own throughput limit (messages per second), and anything over that limit sits in the queue and eventually fails.

  • Slow down the sending rate, or spread sends out over a longer window

  • Use Broadcasts, which pace sending for you, instead of a rapid loop of individual messages from an integration or API

  • Send from additional numbers to spread the volume

  • Contact support about a higher-throughput number or 10DLC campaign tier

30003

Unreachable handset.

The device is off or out of service

  • Retry later

  • Confirm device can receive non-Salesmsg SMS

  • Confirm the number you are sending to is valid - look at enabling PhoneCheckr via your General settings.
    (Additional rates apply.)

30004

Message blocked

The destination carrier or handset refused the message. This is usually because the recipient has blocked your number, or the carrier is blocking traffic to that number.

  • Confirm the recipient still wants to hear from you and hasn’t blocked the number

  • Try reaching them another way (call or email) to confirm the best number

  • Remove the number if the block is permanent

30005

Unknown or inactive number

  • The number is no longer in service

  • There is an issue with the mobile carrier

  • The device you are trying to reach is not on or does not have sufficient signal.

Try alternate number or verify the contact

30006

Landline or unreachable carrier

The number can’t receive SMS

Use only valid numbers (type: mobile, VoIP) and skip sending to Landlines.

30007

Message filtered (blocked)

Message flagged by filters as spam

Review content (remove spammy words), comply with rules

30008

Unknown delivery error

Generic failure with no clear reason

Try sending a shorter message to the phone, with simple content that does not include any special characters.
​
Contact support with message details (Include a minimum of 2-3 messages where a 30008 error was present. Per our carriers' requirements, these messages can be no older than 48 hours at most.

30011

MMS not supported

Recipient can’t receive MMS

  • Reduce Message Size: If the MMS contains large files or unsupported content, try reducing the file size or simplifying the content to fit within the carrier’s MMS limits.

  • Switch to SMS: If MMS is not supported, consider sending a standard SMS (text-only message) instead.

30017

Carrier error

The destination carrier reported a problem on its own network and could not accept or deliver the message. Nothing is wrong with your account or your message content.

  • Wait and retry - these are usually temporary

  • If the same recipient keeps failing, verify the number and try an alternate one

  • Contact support if it persists across many contacts

30019

Content size limit exceeded

The message - almost always an MMS attachment - is larger than the carrier will accept.

  • Compress or resize the image or file before attaching it

  • Send fewer attachments per message

  • Share a link to the file instead of attaching it

30023

Daily Message Cap Reached

Your T-Mobile daily SMS message limit has been met.

Wait until the limit has been reset.

30024

Carrier error

The destination network rejected the message due to a numbering-plan or routing problem on the carrier side.

  • Confirm the number is complete and correctly formatted, including the country code

  • Retry later, or try an alternate number for the contact

  • Contact support if it keeps happening

30032

Toll-Free not verified

You’re using an unverified toll-free number

Complete toll-free verification process

30034

Unregistered 10DLC number

You are sending from a US local (10-digit) number that is not registered to an approved A2P 10DLC brand and campaign. US carriers block unregistered business traffic, so the message never reaches the recipient.

  • Complete your A2P 10DLC registration and make sure the number is assigned to the approved campaign

  • If your registration was rejected, review the 10DLC rejection codes

  • Registration can take several days - messages will keep failing until it is approved

30035

Unregistered 10DLC number

Same family as 30034 - the sending number is not linked to a registered and approved 10DLC campaign, so carriers rejected the traffic.

  • Finish A2P 10DLC registration for your brand and campaign

  • Confirm every number you send from is attached to the approved campaign

  • Contact support if registration is approved but you still see this code

30410

System error

Internal or server-side issue

Wait and retry; contact support if it persists

Other Error Codes

These codes come from the media and system layers, and most of them show up on messages that include an image or attachment.

Code

Description

What’s Happening

What to Try

11200

System error

Something went wrong while the system was retrieving or processing the message, most often the attached media file.

  • Re-upload the attachment and resend

  • Try sending as text only to confirm the attachment is the cause

  • Contact support if it repeats

11205

System error

The system could not reach the resource it needed while sending, usually a hosted media file or an endpoint that timed out.

  • Wait a moment and resend

  • Re-attach the file rather than reusing an old link

  • Contact support if it persists

11751

Content size limit exceeded

The MMS attachment is too large to be sent. Carriers cap MMS media size, and oversized files are rejected before delivery.

  • Compress or resize the image or video

  • Attach one smaller file instead of several

  • Send a link to the file instead of the file itself

12300

Invalid content type

The attached file is a format that MMS does not support, or the file type could not be recognized.

  • Use a widely supported format such as JPG, PNG, or GIF

  • Convert documents to an image, or share them as a link

  • Re-save the file and upload it again if the format should be supported

63010

System error

An internal error occurred in the messaging channel while the message was being processed.

  • Wait and retry

  • Contact support with the message details if it keeps failing

International Texting Failure

If your international texting isn’t working, the most common reason is that the International Texting feature is turned off in your settings.

When international texting is disabled, Salesmsg will automatically block outgoing messages to all countries except:

  • United States (US)

  • Canada (CA)

  • United Kingdom (GB)

  • Australia (AU)

✅ How to fix it:
Check your account settings and make sure the Extended International Texting feature is enabled if you need to message contacts outside of the four supported countries.

"Unable to send message to this region"

Why does it say “Unable to send message to this region”?

This error means that messages can’t be sent to numbers from that country - either because the region isn't supported or is restricted by platform rules.

Common reasons:

  • The destination country isn’t allowed in your current messaging settings

  • The sender’s phone number doesn’t support messaging to that region

  • Compliance rules or platform policies restrict delivery to certain countries

✅ What to do:
Check your account settings or contact support to see if messaging to that country can be enabled or if you need a different type of phone number (like one that supports international messaging).

"Insufficient_funds"

This error pops up when your account doesn’t have enough credits to send a message or complete an action (like a call or broadcast).

Salesmsg services run on prepaid credits, so if your balance is too low, the system can’t process the message - and you’ll see this error.

✅ How to fix it:
Just top up your account by adding more credits. Once your balance is restored, you’ll be able to send messages again.

"Stopped by user"

What it means:
This message was part of a broadcast campaign that was manually stopped before it finished sending.

Why it happens:
You (or someone on your team) clicked “Stop” on the broadcast. That cancels any messages that hadn’t been sent yet.

✅ How to fix it:
If this was accidental, you’ll need to create a new broadcast to resend the messages that were canceled.

"Duplicate_message"

This error shows up when the system detects that the exact same message is being sent again - usually from an external integration or automation.

To protect your contacts from getting spammed, Salesmsg has a deduplication system that blocks identical messages sent too close together.

✅ How to fix it:
Change up the message slightly (even a small edit can help), or adjust your automation to avoid sending the same content more than once in a short period.

"Unknown_bad_number"

This error pops up when the phone number you're trying to message is invalid or unrecognized by the system.

It usually means there's a problem with the number — like missing a country code, having the wrong format, or the number being disconnected or inactive.

✅ How to fix it:
Double-check the number format (including the country code) and make sure it’s a valid, active mobile number. Using a number validation tool like PhoneCheckr can help avoid this error.

⚠️ Common Provider Errors

"Provider_error"

[HTTP 400] Unable to create record

This error means your message couldn’t be sent because there’s an issue with the phone number itself.

Why it happens:

  • The number isn’t enabled for SMS on your account.

  • The number isn’t properly linked or provisioned in the system.

  • The number is a landline, VoIP, or another type that can’t receive SMS.

  • There may be an internal system issue preventing the number from being verified.

How to fix it:

  • Make sure the number is correctly set up and provisioned for SMS.

  • Verify that the number is supported by your messaging provider.

❌ Trying to send a message to a landline

Landline numbers cannot receive text messages. If you try to send an SMS to a landline, it will fail.

Tip: Use a mobile number that supports SMS for messaging in Salesmsg.

❌ US-based short code restriction

If you see this error, it means your US short code can only send messages to US phone numbers. Short codes (5-6 digit numbers) are region-specific, so sending to international numbers isn’t allowed.

Tip: Only send messages to numbers within the country your short code is registered in.

❌ Message contains blacklisted words

Your message includes words or phrases that the system doesn’t allow. These could be related to spam, illegal activities, adult content, or other prohibited topics.

Why it happens:

  • The system has an internal blacklist of restricted keywords.

  • Your message may violate platform policies.

How to fix it:

  1. Check your message – Look for words that might trigger the blacklist (common ones relate to drugs, adult content, or spam).

  2. Modify the wording – Rephrase your message to remove restricted terms.

  3. Contact support – If you’re unsure which words are blocked, reach out to Salesmsg support for guidance.

Frequently Asked Questions

Why am I being charged for failed messages?

Starting September 30, 2024, some messages that return a “Failed” status will include a Message Processing Fee of $0.001.

This small fee is a pass-through cost from the carrier - not a charge from Salesmsg. It covers the processing that happens even if the message can’t be delivered (like carrier-level handling or delivery attempts).

💡 Only certain types of failures incur this fee. It’s not charged on every failed message.

Need Help? ✋🏻

Contact us on live chat or send an email to us at [email protected].

Related Articles
Did this answer your question?