Long SMS messages are text messages that exceed the character limit of a single SMS part. At BulkSMSOnline.com, long SMS messages can be sent up to a maximum of 5 SMS parts, depending on the message length, character encoding, destination country, and selected SMS route.

 

Even when a long SMS is divided into multiple parts for delivery, the recipient will usually see it as one complete message on their mobile phone. However, the message is still charged based on the total number of SMS parts used.

 

What Is a Long SMS Message?

A long SMS message is any SMS that is longer than one standard SMS part. When your message exceeds the single-part limit, it is automatically split into smaller SMS segments. These segments are sent through the SMS network and then reassembled on the recipient’s phone where supported.

This feature is useful when you need to send detailed customer notifications, appointment reminders, delivery updates, payment alerts, OTP instructions, promotional messages, or important business announcements that cannot fit into one short SMS.

 

SMS Character Limits for Long Messages

The number of characters allowed in an SMS depends on whether the message uses GSM encoding or Unicode encoding.

SMS Type Single SMS Limit Long SMS Limit Per Part Maximum Supported Parts Approximate Maximum Length
GSM / English SMS Up to 160 characters Around 153 characters per part Up to 5 parts Around 765 characters
Unicode SMS Up to 70 characters Around 67 characters per part Up to 5 parts Around 335 characters

 

Why Does a Long SMS Have Fewer Characters Per Part?

A single English SMS can contain up to 160 GSM characters. However, when the message becomes longer and is split into multiple parts, a small amount of space is used by technical joining information. This joining information helps the recipient’s phone combine the SMS parts into one complete message.

Because of this, long GSM messages usually allow around 153 characters per part instead of the full 160 characters. Unicode messages work in a similar way. A single Unicode SMS can contain up to 70 characters, but long Unicode messages usually allow around 67 characters per part.

 

How Are Long SMS Messages Charged?

Long SMS messages are charged according to the number of SMS parts used. If your message uses 2 parts, it will be charged as 2 SMS parts. If it uses 3 parts, it will be charged as 3 SMS parts, and so on, up to the maximum supported parts.

For example:

  • A GSM English SMS within 160 characters is usually charged as 1 SMS part.
  • A GSM English SMS longer than 160 characters may be split into 2 or more SMS parts.
  • A Unicode SMS longer than 70 characters may be split into 2 or more SMS parts.
  • A message containing emojis, Arabic text, Chinese text, or special symbols may be counted as Unicode.

Before sending a large campaign, it is important to check the message length and estimated number of SMS parts so you can understand the expected credit usage.

 

Will the Customer Receive One Message?

In most cases, yes. Although the SMS is technically divided into multiple parts during delivery, the recipient’s phone normally joins the parts together and displays the message as one complete SMS.

However, this may depend on the recipient’s mobile device, mobile operator, destination country, and network support. Some older phones or certain networks may display long SMS messages differently.

 

Why Did My SMS Use More Credits Than Expected?

Your SMS may use more credits than expected if the message becomes longer than one SMS part or if it changes from GSM encoding to Unicode encoding.

Common reasons include:

  • The message is longer than 160 GSM characters.
  • The message contains Unicode characters.
  • The message includes emojis.
  • The message includes Arabic, Chinese, Russian, or other non-GSM text.
  • The message contains smart quotes copied from Word, websites, or email templates.
  • The message contains special symbols or unsupported characters.

If your message changes to Unicode, the available character limit becomes much lower, which can increase the number of SMS parts and credits used.

 

Examples of Long SMS Calculation

Here are simple examples to help you understand how long SMS messages may be counted:

  • 150 English GSM characters: Usually 1 SMS part.
  • 200 English GSM characters: Usually 2 SMS parts.
  • 320 English GSM characters: Usually 3 SMS parts.
  • 65 Unicode characters: Usually 1 SMS part.
  • 100 Unicode characters: Usually 2 SMS parts.
  • 250 Unicode characters: Usually 4 SMS parts.

These examples are for general guidance. The final SMS part count can depend on the actual characters used in the message.

 

How to Reduce SMS Parts and Save Credits

To reduce SMS parts and control campaign cost, keep your message short and avoid unnecessary characters. A shorter SMS is often easier for customers to read and may perform better for marketing campaigns.

  • Keep the message clear and direct.
  • Avoid emojis unless they are necessary.
  • Use standard English characters when possible.
  • Remove unnecessary spaces, symbols, and repeated punctuation.
  • Avoid copying text from documents that may contain hidden formatting.
  • Check message length before sending.
  • Test the SMS before sending to a large list.

 

Does Route Type Affect Long SMS Delivery?

The selected SMS route may affect delivery speed, sender ID behavior, delivery report availability, and how the message is handled by destination networks. If you are sending long SMS messages for important notifications, OTP instructions, or customer alerts, choosing the correct route is important.

You can learn more about route options on the SMS Routing page.

 

Can I Send Long SMS Through the API?

Yes. You can send long SMS messages through the BulkSMSOnline API, as long as the message does not exceed the supported maximum parts limit. When sending by API, your system should check message length, encoding type, recipient country, selected route, and expected SMS parts before submitting the message.

For API sending, REST API, HTTP API, SMPP, delivery reports, and webhook setup, visit the BulkSMSOnline Developers page.

 

Check Pricing Before Sending Long SMS

Because long SMS messages are charged based on the number of SMS parts, the final cost depends on the message length, destination country, selected route, and total number of recipients.

For example, if your SMS uses 3 parts and you send it to 1,000 recipients, the campaign may use 3,000 SMS parts in total.

You can review available SMS rates on the Bulk SMS Pricing page.

 

Country Restrictions for Long SMS

Some countries and mobile operators may have specific rules for sender IDs, Unicode messages, marketing content, links, OTP traffic, and long SMS delivery. Before sending a large campaign, it is recommended to test the message and review destination-specific requirements.

You can browse country-specific SMS information through the Bulk SMS Countries section.

 

Need Help With Long SMS Messages?

If you are not sure why your SMS is being split into multiple parts, why more credits were deducted, or why your message changed to Unicode, our support team can help you review the issue.

For faster support, please provide your message text, destination country, sender ID, selected route, message ID, sending time, and delivery report status.

You can visit the BulkSMSOnline Help Center or contact our team through the Contact Us page.

 

Frequently Asked Questions

How many parts can a long SMS have?

BulkSMSOnline supports long SMS messages up to a maximum of 5 SMS parts.

How many characters are allowed in one English SMS?

A standard GSM English SMS can contain up to 160 characters in one SMS part.

How many characters are allowed in long English SMS?

When a GSM English SMS becomes long and is split into multiple parts, each part usually allows around 153 characters.

How many characters are allowed in one Unicode SMS?

A Unicode SMS can contain up to 70 characters in one SMS part.

How many characters are allowed in long Unicode SMS?

When a Unicode SMS becomes long and is split into multiple parts, each part usually allows around 67 characters.

Will the customer see long SMS as one message?

In most cases, yes. The recipient’s phone usually joins the SMS parts and displays them as one complete message.

Are long SMS messages charged as one SMS?

No. Long SMS messages are charged based on the number of SMS parts used, even if the customer sees the message as one complete SMS.

Why did my message become Unicode?

Your message may become Unicode if it includes emojis, Arabic text, Chinese text, special symbols, smart quotes, or non-GSM characters.

Can I send long SMS through BulkSMSOnline API?

Yes. Long SMS messages can be sent through the BulkSMSOnline API, but your application should check the message length, encoding, route, and expected SMS parts before sending.