# A text message was not delivered

> Point to Not delivered under the message to see the reason. Common causes are a landline, an opt-out, an unreachable phone, a blocked country or low credits.

Source: https://useline.io/help/troubleshooting/sms-not-delivered  
Section: Troubleshooting  
Last updated: 2026-11-06

When a text fails, the Inbox shows **Not delivered** under the message. Point to **Not delivered** to see the reason and the error code. Then use the table below to fix it.

## Find the reason

1. Open the conversation in the **Inbox**.
2. Find the message with **Not delivered**.
3. Point to **Not delivered**. A tooltip shows the reason and the error number.

To send the same text again, select **Retry**. Line sends it as a new message.

## Reasons and fixes

| Error | What it means | What to do |
|---|---|---|
| 21610 | The recipient replied STOP. | The recipient must text START to your number. Then you can text them again. |
| 21614, 30006 | The number cannot receive texts. It can be a landline. | Call the customer, or use another channel. |
| 21211, 21421 | The number is not valid. | Check the digits and the country code. |
| 30003 | The phone is off, out of coverage or no longer active. | Try again later. |
| 30005 | The number does not exist or is no longer in use. | Ask the customer for a new number. |
| 30004, 30007 | The carrier blocked or filtered the message. | Change the wording. Do not use all capitals or many links. |
| 30001, 30008 | The carrier did not deliver it, and gave no clear reason. | Select **Retry**. |
| 21408 | Texts to that country are not turned on for your workspace. | Contact support@useline.io. |

## The text does not send at all

Some problems stop the text before it leaves. Line then shows a message in the composer or the dialog.

**"Insufficient credits".** Your credit balance is too low. An Owner or Admin can buy credits in **Settings** > **Billing & Usage**.

**"This looks like a landline."** Line thinks the number is a UK landline. A landline usually cannot receive texts. Select **Send anyway** only if you are sure that the number can receive texts.

**"Can't send to" a country.** Texts to that country are not turned on for your workspace. Contact support@useline.io.

**"No business number assigned to this account".** Your workspace has no active number. Check the number status in **Channels** > **SMS**.

## A picture or file did not send

Texts on UK numbers cannot carry pictures or files. Send files by email, WhatsApp or Web Chat.

## Still not working

Contact support@useline.io. Include the recipient number, the time you sent the text and the error number.

## Related articles

- [Send and reply to text messages](https://useline.io/help/messaging/send-sms.md): Send an SMS from the Inbox with New message, or reply in the conversation. Texts leave from your Line number and cost credits per segment.
- [How credits and the credit wallet work](https://useline.io/help/billing/credits-and-usage.md): Line is prepaid. Calls, texts, WhatsApp, extra email and AI replies use credits from your wallet. One credit is 1p. Automatic top-up refills it.
- [Use the shared Inbox](https://useline.io/help/inbox/shared-inbox.md): The Inbox holds every customer conversation on SMS, calls, WhatsApp, email and Web Chat in one list. Open a conversation to read it, reply, or close it.
- [Calls do not ring](https://useline.io/help/troubleshooting/calls-not-ringing.md): Check your status, the browser tab and sound, the call workflow of the number, and your credits. Line rings only Available people in a Ring step.