SMS Size & Character Limits

As texting continues to evolve, so do the message size, character counts, and message segments/counts that are enforced by the carriers. At Textel, we integrate with a variety of carriers to offer our clients a wider range of toll-free, domestic long code and short code options, as well as international number options. 

We know that understanding how SMS message counts are calculated and split can be confusing, especially when it impacts your message usage and billing. In this article, we will explain how our platform enforces these SMS message sizes and character limits into the actual message segments that are sent to the carrier and billed.

SMS Message Transit Breakdown

It is important to note the difference between what carriers accept as a single message container versus the message segments that they split the content into as they deliver it through the carrier network and to the mobile phone. In the Textel platform for example, we allow you to compose a single message container of up to 600 characters. The Direct Connect Aggregator (the carrier where your A2P number is set up), receives the full message container but has to break it up into smaller SMS segments (if over 160 characters) in order to deliver it to the mobile carrier of the message recipient. The mobile carriers will then receive the segments and prior to sending it to the mobile number, they will rejoin the segments together and deliver it to the device as one, contained message.

SMS Character Limits & SMS Counts

At the most fundamental level a single SMS message is 160 characters. This is enforced across all mobile carriers. When a text exceeds 160 characters, it will need to be broken down into 153 character SMS message segments in transit, even if the carriers rejoin it to deliver it as a single text to the mobile contact. Each segment represents a single SMS message that you would be billed for in your Message Usage. 

Message CompositionSegment Character LengthNotes
Single SMS message 160 characters or less, no emojis160 charactersAny SMS message composition that is 160 characters or less is considered one, single message by the carriers.
SMS message composition that exceeds 160 characters153 charactersMessage compositions that exceed 160 characters, the carriers automatically split the composition into 153 character SMS message segments.
Message containing emojis70 characters
(if more than one segment is needed to send entire composition, it reduces to 66 characters)
Standard emojis count as 2 characters. They also change the message encoding, causing the SMS segment character count to reduce even further.
Message containing unicode or non-Latin characters70 characters
(if more than one segment is needed to send entire composition, it reduces to 66 characters)
These types of non-Latin characters require special encoding that reduce the character count, meaning a single SMS message would be 70 characters.

In our interface and API, we allow you to compose up to a 600 character text. This allows you to craft message compositions at that length that will ultimately be delivered to your mobile contacts as a single text. Despite the carriers breaking it up in transit and charging for the individual SMS segments, by our platform sending it in a single message composition container, it preserves the ability to send longer form messages to mobile contacts without forcing you to compose individual 160 character SMS segments that would be delivered separately to the contact.

Example SMS Message Scenarios

511 character message composition without emojisSMS Count = 4
511 characters results in 4 SMS messages in the carrier system because the segments are split at 153 characters. 
134 character message composition with emojisSMS Count = 2
Emojis count as 2 characters when they are interpreted in the carrier system, reducing the character count per SMS message to 70 characters.
404 character message composition with an image attachmentMMS Count = 1
Attaching any form of media automatically converts the message type to MMS. More info on MMS message sizes.

SMS Counter Display

Within the Textel platform, anywhere that there is message composition box, you will see an updated version of our character counter. It has now been enhanced to provide real-time feedback as you type your message on how many characters you've included and how many SMS messages it will count as. 

As you add emojis or continue typing, the counter will update with each character, informing you proactively how many SMS messages will be created in the carrier system (and thus how many you will be billed for).

Message Composition Box

We have updated the character counter to also include an SMS Counter with a link to this article to explain how message segments are calculated.

Blast Campaign Feedback

At the bottom of the Blast creator page near the Save button, we have added feedback on the collective count of messages that will be sent as part of your campaign.

Dynamic Parameters

Because we allow you to use dynamic parameters in your messages, we will not know the exact character/SMS message count of the final message composition until the replacement is done on message send. We count the characters of the dynamic parameter placeholder when we provide the real-time feedback. Actual message and character counts will be set on send.

Usage Reporting

Within our reporting and usage graphs, we are displaying the message counts to reflect the SMS Counts described above. They represent what the carriers return as actual SMS message segments and align with how we are charged per message.

These are the areas of the platform where you can view actual message usage counts.

Message Usage Details on Manage Account Page

Admins can go to the Manage Account page and view your current message usage information compared to your plan. The counts used or scheduled in this graph reflects the SMS counts as described above.

Homepage Dashboard Stats

When logging in, the big number statistics that you see on the dashboard also reflect the message counts as broken down by the carriers.

Visual Summary Reports

In our Reporting section, one of the report categories is Visual Summary. These reports reflect the counts as calculated by the carriers.

Blast Usage Check Graph

When setting up a campaign in Blast, there is an opportunity to check your current message usage against your plan. This graph will also reflect the true SMS message counts as billed by the carriers.

Do you have questions regarding SMS message segmentation? This tutorial will assist users in understanding how SMS messages are broken down into segments, including examples of text message types ranging from 160 characters or less to 160+ characters. Also included is the explanation of how emoji use will affect the overall segment count and how images affect message conversion to MMS. Reporting tools and resources within the Textel platform are shared, including the use of dynamic fields as they relate to character counts.

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