If you are unable to send or receive SMS in CloudTalk, this guide will help you identify what is causing the issue and how to resolve it. It covers the most common symptoms, technical limitations, and country-specific restrictions that may affect SMS delivery.
For a complete overview of SMS behavior in CloudTalk, also see Text Messaging.
Symptoms
You may notice one or more of the following:
When sending SMS
The message fails immediately
The SMS appears as “Sent” but the recipient does not receive it
Messages deliver to some numbers but not others
A long message becomes multiple separate messages
The sender number changes unexpectedly
When receiving SMS
No inbound messages appear in the CloudTalk app
You receive some messages but not others
Verification codes (OTP / 2FA) never arrive
Older SMS conversations disappear from the app
How SMS Works in CloudTalk
CloudTalk supports P2P (peer-to-peer) conversational SMS.
However, SMS functionality varies by:
country
number type
destination network
telecommunication regulations
Before troubleshooting, please note:
Not all CloudTalk numbers support SMS
Not all countries support international SMS
Many services do not send OTP/2FA codes to VoIP numbers
Some carriers rewrite the sender number to ensure delivery
Long or Unicode messages are split into fragments
Trial accounts can send up to 10 SMS fragments only
Root Causes
⚠️ Your number is not SMS-enabled
Not every CloudTalk number supports SMS. Some numbers are voice-only because of the rules and capabilities in the country where they were purchased. For example:
Some local numbers in certain countries do not allow SMS through VoIP providers.
Many toll-free numbers support voice only and do not support SMS at all.
Some mobile number ranges can only send outbound SMS but cannot receive them.
In some countries, SMS can only be delivered domestically and not internationally.
Older numbers on your account may have been purchased before SMS coverage was available for that region.
This is expected behavior and depends on local telecom regulations, not on your CloudTalk plan.
To check SMS availability for your country or number type, you can review the CloudTalk SMS-capable number coverage.
⚠️ Destination country limitations
Each country has its own rules about what kind of SMS can be delivered. Some limitations you may come across include:
International SMS not supported
Only certain number types allowed (for example, mobile only)
No long messages or no multi-fragment messages
Local networks rewriting the sender number
If SMS work to one country but not another, this is often the reason.
⚠️ CloudTalk trial limits
Free trials include up to 10 SMS fragments for testing.
Once the limit is reached, SMS will stop working until the account is upgraded.
The limit cannot be extended.
⚠️ Message content is prohibited
Some types of content are blocked automatically by destination carriers, especially in USA / Canada. These restrictions apply even when sending SMS manually from CloudTalk.
Examples of restricted or blocked content include:
high-risk financial content
affiliate or lead-generation marketing
gambling
adult content
debt-related content
risky or misleading marketing phrases
⚠️ OTP / 2FA messages cannot be received
CloudTalk numbers are VoIP-based, and many banks, apps, and online services do not send one-time passwords (OTP) or two-factor authentication (2FA) codes to VoIP numbers. Even if regular SMS works, verification codes sent by SMS may never arrive.
If you need to complete verification, many services allow you to request an authentication phone call instead of an SMS code. These calls usually work with CloudTalk numbers.
If possible, we still recommend using a personal mobile number or another authentication method for critical account access.
Learn more about OTP / 2FA limitations here.
⚠️ The message is too long or uses special characters
Messages with emojis, accents, or non-standard characters use a different character set, which reduces the number of characters allowed in a single SMS.
Standard characters: up to 160 per SMS
Unicode characters: up to 70 per SMS
If your message exceeds these limits, it will be split into multiple fragments. Some destinations do not support combining fragments, which may cause the full message not to be delivered.
⚠️ The sender of the inbound message uses an unsupported format
CloudTalk cannot receive SMS from:
alphanumeric senders (names instead of numbers)
short codes
certain automated systems
apps that mask their sender ID
This is why one-time passwords, login verification codes, and two-factor authentication messages often do not arrive.
Only SMS sent from a regular long-code phone number can be received.
⚠️ SMS are not visible in the CloudTalk app
CloudTalk Phone shows only a limited number of recent SMS conversations to keep the app fast and responsive. The app displays up to 100 recent conversations in total:
50 most recent inbound conversations
50 most recent outbound conversations
Once these limits are reached, older conversations automatically roll out of view. Individual conversations also have limits on how many messages can be displayed.
These older SMS are not deleted, they simply no longer appear in the app. If you need access to historical messages that are no longer visible, CloudTalk Support can export them on request.
⚠️ Local carriers may change the sender number
When sending SMS internationally, some networks replace your sender number with a different one to ensure delivery. This is common and not a CloudTalk issue.
However, it can cause confusion if the recipient tries to reply to the modified number and the reply never reaches you.
Step-by-Step Troubleshooting
1. Check if your number supports SMS
CloudTalk Phone will show you immediately if a number does not support SMS.
You can check this directly in the app:
Open CloudTalk Phone (Desktop or Web).
Look at the bottom navigation bar, where the icons for Calls, Contacts, Dialpad and Messages are located.
If SMS is not supported for the number you are currently using, the Messages icon will be greyed out and cannot be clicked.
When you hover your cursor over the Messages icon, a small tooltip appears explaining that SMS is not supported for this number.
This is the quickest way to confirm that your number is voice-only or does not include SMS capability.
If the Messages icon is active (in color), the number is SMS-capable and you can start sending and receiving text messages.
Can I switch a voice-only number to SMS-enabled?
In most cases, capabilities cannot be changed because they depend on the telecom infrastructure in the country where the number originates.
However, you can replace your number with another number that fully supports SMS if the country and number type allow it.
How to get an SMS-capable number
Go to Numbers > Get a number.
Select the same country as your current number.
Choose a number type that supports SMS (for example, mobile instead of local, if available).
If you do not see any SMS-capable options, submit an assisted request and mention that you specifically need SMS support.
Your Account Manager or Support can help you choose a number type that supports SMS in your region.
2. Test sending SMS to multiple destinations
Send SMS to:
your own mobile
a number in the same country as your CloudTalk number
a number in a different country
If some messages arrive and others do not, the issue is likely country-specific or related to the destination’s mobile network.
3. Shorten the message and avoid special characters
If the message is long or includes emojis, accented characters, or formatting, try simplifying it.
This reduces the number of fragments and helps with delivery in countries that do not support multi-fragment messages.
4. Review SMS content
Some types of message content are blocked by destination carriers, especially in countries with strict filtering rules. If you are sending regulated or sensitive content, check whether it falls into a restricted category, including:
financial services or loan offers
affiliate or lead-generation marketing
cannabis / CBD
gambling or betting
3rd-party debt collection
sensitive categories such as sex-related content, hate-related content, alcohol, firearms, or tobacco
If a message includes restricted content, it may be filtered or blocked without any delivery error.
5. Try receiving an SMS from a regular mobile number
If you are not receiving inbound SMS:
Ask someone to send a message from a standard mobile number
Do not test with short codes or app verification systems (these usually will not work)
If long-code messages arrive but app verification messages do not, the behavior is expected.
6. Check SMS visibility in the CloudTalk app
If messages were previously visible but no longer appear, it may simply mean that the app has reached its limit for how many SMS conversations and messages it can display. To keep CloudTalk Phone fast and stable, only a certain number of recent conversations and messages are shown, and older ones are automatically hidden from view.
These older SMS are not deleted. They just no longer appear in the app.
If you need access to older SMS, CloudTalk Support can export them for you.
When to Contact Support
Contact CloudTalk Support if:
Your number is SMS-enabled but cannot send or receive any SMS
SMS fail to all destinations
Inbound SMS worked previously and suddenly stopped
Messages appear as “Sent” but never deliver
You need older SMS exported from the database
You suspect country-specific blocking or carrier restrictions
Include:
Your number
Destination number(s)
SMS message example
Timestamp of the failed attempt
Screenshot of the message in CloudTalk
Whether you are on trial or a paid plan