---
title: What does it mean when a number is invalid? 
description: SMS Global Knowledgebase
---

[![](https://cdn.craft.cloud/ff00d28e-6061-427e-b58d-8267ebeaad6b/builds/a173c27c-7ed2-40a3-b553-3262aea64d9e/artifacts/dist/img/logo/sms-global-logo.svg)](https://smsglobal.com?hsLang=en-au)

 smsglobal.com [Talk to an expert](https://www.smsglobal.com/contact?hsLang=en-au)  Talk to an expert

[Skip to content](https://hs.smsglobal.com/what-does-it-mean-when-a-number-is-invalid-smsglobal-help-center#main-content)

[![SMSGLOBAL LOGO WHITE-2](https://hs.smsglobal.com/hs-fs/hubfs/SMSGLOBAL%20LOGO%20WHITE-2.png?width=500&height=100&name=SMSGLOBAL%20LOGO%20WHITE-2.png)](https://www.smsglobal.com/?hsLang=en-au)

Open main navigation

Close main navigation

- [Contact us](https://www.smsglobal.com/contact/)

[Contact us](https://www.smsglobal.com/contact/?hsLang=en-au)

 Advice and answers from the SMSGlobal Team

- There are no suggestions because the search field is empty.

1. [SMS Global Knowledgebase](https://hs.smsglobal.com/?hsLang=en-au)
2. [Sending a SMS](https://hs.smsglobal.com/sending-a-sms?hsLang=en-au)

- [Sending a SMS](https://hs.smsglobal.com/sending-a-sms?hsLang=en-au)
- [Sender ID](https://hs.smsglobal.com/sender-id?hsLang=en-au)
- [API and Integration](https://hs.smsglobal.com/api-and-integration?hsLang=en-au)
- [Email to SMS](https://hs.smsglobal.com/email-to-sms?hsLang=en-au)
- [Reporting](https://hs.smsglobal.com/reporting?hsLang=en-au)
- [Sub-Accounts](https://hs.smsglobal.com/sub-accounts?hsLang=en-au)
- [Delivery Receipts](https://hs.smsglobal.com/delivery-receipts?hsLang=en-au)
- [Billing and Payments](https://hs.smsglobal.com/billing-and-payments?hsLang=en-au)
- [Contact Lists](https://hs.smsglobal.com/contact-lists?hsLang=en-au)
- [Managing Opt-Outs](https://hs.smsglobal.com/managing-opt-outs?hsLang=en-au)
- [Campaigns](https://hs.smsglobal.com/campaigns?hsLang=en-au)
- [Templates](https://hs.smsglobal.com/templates?hsLang=en-au)
- [MMS](https://hs.smsglobal.com/mms?hsLang=en-au)
- [Voice](https://hs.smsglobal.com/voice?hsLang=en-au)
- [Laws and Regulations](https://hs.smsglobal.com/laws-and-regulations?hsLang=en-au)
- [Video Tutorials](https://hs.smsglobal.com/video-tutorials?hsLang=en-au)
- [Account Settings](https://hs.smsglobal.com/account-settings?hsLang=en-au)
- [Understanding Unicode Messages](https://hs.smsglobal.com/understanding-unicode-messages?hsLang=en-au)

# What does it mean when a number is invalid? 

## Understand why your SMS status is flagged as Invalid Number

The recipient's number is invalid and cannot be recognised by our system for delivery.

This may be caused if:

- The mobile number is not in the [correct international format,](https://hs.smsglobal.com/what-format-do-my-mobile-numbers-need-to-be-in-to-send-an-sms-smsglobal-help-center?hsLang=en-au) it was too long/short, or it was entered incorrectly.
- The customer may have also opted out from receiving text messages. Please see the knowledgebase category on[Managing opt-outs in MXT.](https://intercom.help/smsglobal/en/collections/2918254-managing-opt-outs)

Different countries have strict regulations on message sending; please see the[Laws and Regulations](https://intercom.help/smsglobal/en/collections/2920367-laws-and-regulations) knowledgebase category for more information.

If a certain number is on a country's ***'Do not call list'***, your message will not send.

If you require a mobile number lookup, please create a ticket for our support team with details such as:

- Your SMSGlobal username
- A list of phone numbers you wish to look up (Excel or CSV format is preferred)
- Countries that you're trying to send to
- Sender ID that you're using for SMS

[![SMSGlobal](https://hs.smsglobal.com/hs-fs/hubfs/SMSGlobal-logo-black-transp.png?width=200&height=56&name=SMSGlobal-logo-black-transp.png "SMSGlobal")](http://smsglobal.com?hsLang=en-au)

[mailto:support@email.com](mailto:support@email.com)

Copyright © 2026, SMSGlobal

![](https://analytics.twitter.com/i/adsct?txn_id=nxnc4&p_id=Twitter&tw_sale_amount=0&tw_order_quantity=0) ![](https://t.co/i/adsct?txn_id=nxnc4&p_id=Twitter&tw_sale_amount=0&tw_order_quantity=0)

[![SMSGlobal](https://cdn.craft.cloud/ff00d28e-6061-427e-b58d-8267ebeaad6b/builds/a173c27c-7ed2-40a3-b553-3262aea64d9e/artifacts/dist/img/logo/sms-global-logo-light.svg)](https://smsglobal.com/?hsLang=en-au)

 © Copyright . SMSGlobal. All rights reserved.

[smsglobal.com](https://smsglobal.com/?hsLang=en-au) [Talk to an expert](https://smsglobal.com/contact/?hsLang=en-au)