The idea of a company performing marketing is to sell its product. To do this, a company should detail what makes their product the best and why a consumer needs that specific product over a competitor’s. For a company to achieve that, the advertising message needs to be both informative and enticing. However, if a company uses an SMS marketing solution, that can be difficult, as an SMS message can only have 160 characters. A lack of alphanumeric characters means the message needs to be short, while still able to do its job, which is not an issue compared to other marketing means, such as email marketing. However, if used correctly, perhaps the SMS character limit is not as inconvenient as many feel it is.

Why Is There an SMS Character Limit?

Tracing back the origin of the SMS character limit is not easy, though there are two generally accepted stories. All that can be certain is that the initial concept of SMS got approved in 1982, as GSM wanted to bring text functionality to mobile devices. From that first idea, SMS was born and so was the character limit that came with it. But why is there a character limit?

The Perfect Message Size

SMSHyperloop-SMS Character Limit

The first reason for the SMS character limit goes back to Friedhelm Hillebrand, who was one of the two developers of the concept of SMS, with the other being Bernard Ghillebaert. They both worked for Global Systems for Mobile Communications or GSM for short. Friedhelm got tasked with setting the character limit that his new text messaging system would use. To do this, he took out his typewriter and began to type out random questions and statements. After doing this for some time, he concluded that 160 characters were enough to get most messages across.  However, Friedhelm also wished to confirm this, before settling for the final character limit, as any product tester should. To do this, he examined a selection of postcards, one of the mediums at the time used for sending short messages. Upon reviewing these postcards, Friedhelm discovered that the average character count was also around 160. For one last form confirmation, Friedhelm examined messages sent via Telex, which do not have a character limit.  Despite that, messages sent via the Telex system still tended to have a maximum character count that came in at around 160 characters. Satisfied that 160 alphanumerical characters would suffice, Friedhelm returned to GSM with his findings and that was history.

Technical Limitations

The second story is somewhat more technical than observing previous messages sent by other means, though still routes back to the GSM, and Friedhelm Hillebrand and Bernard Ghillebaert. In 1984, when SMS got conceived, GSM already had the cellular infrastructure in place to allow for telephone calls to be made via cellular towers. This system got optimized for telephone systems, translating packets of data into the actual phone calls. These packets of data come with limited space, with 140 bytes remaining once the call information gets removed. This additional space was going to waste, and Friedhelm decided to use it for carrying SMS messages, instead of creating a whole new infrastructure for the new medium. One character in the SMS was the equivalent of one byte, so a 140-character limit got set, as there were 140 bytes to spare. As GSM technology advanced, 160 bytes became available, which is how the 160-character limit came to be.


As stated above, the character limit of the SMS messages went from 140 characters to 160 characters. The invention of a new GSM encoding system, the GSM-7, was the reason for this. GSM-7 takes the most commonly used letters, numbers, and symbols, and packs them into multiple 7-bit packets.  A single SMS message gets transmitted in 140 8-bit octets, which allows an SMS text message sent with GSM-7 encoding to have 160 GSM characters. GSM-7 supports the standard alphabet, meaning it only works for English and other Western-European languages. A message sent with a local language will receive Unicode encoding, with more on that below.


UCS-2 is a form of text message encoding that comes from Unicode, and use the UCS character set, which contains many more characters than GSM-7. Messages sent with UCS-2 have each of their characters converted into fixed-length packages of 16 bits, or 2 bytes. UCS-2 is what a GSM network, or an SMS marketing platform, will rely on if the message is not suited for the above GSM-7. UCS-2 encoding usually gets used because the text message getting sent has characters that are not part of the GSM-7 encoding language. Words that get written in Chinese, Japanese, or the Cyrillic alphabet are just some examples of when a message gets sent with UCS-2 encoding. A message that gets typed out in GSM-7, though has a single UCS-2 character, whether by accident or intentionally, will get sent with UCS-2 coding. Unfortunately, as stated, each character sent with UCS-2 comes as 2 bytes. An SMS message gets transmitted as a 140 octets package, which means a UCS-2 Unicode message can only have 70 Unicode characters, which can lead to multiple messages if the user intended to send a GSM-7 message.

What Happens If the Message Exceeds the Character Limit?

A single text message consists of 160 characters, assuming it meets the specifications of GSM-7 encoding. However, the entire text message can go up to 918 characters. Any message that is over the 160 characters will get broken down into multiple message parts. From there, either the SMS messaging software or GSM network will charge the sender as if several separate messages got sent, with each of these multiple messages known as a message segment. When a large message gets split, each message will get broken down into 153 characters.

Converting SMS to MMS

Some mobile service providers take large messages with over 160 characters, and instead of sending multiple text messages, convert the message into MMS. MMS messages or multimedia messaging service messages get used when a standard SMS message doesn’t work. MMS messages work on the same system as SMS, though they come with a much higher memory limit of 500 kb or 1,600 characters. MMS messages get used for sending pictures, videos, audio files, and of course, text messages of more than 160 characters. This data limit allows a single message to be much larger. However, because the data processing by the multimedia message service center is more significant, these messages can be expensive when compared to SMS messages and are very rarely included as part of a mobile carrier plan. 

Dealing With a Word Count in Mobile Marketing

A company performing an SMS campaign needs to consider the word count of its message more than anyone, because the more messages they send, the more the marketing campaign will cost, so it’s a waste for a company to go over the word count. Typically, when a company performs SMS marketing, they use a mobile marketing service that can allow them to send multiple messages at once. Those messaging services come in the form of either a long code or short code system.

Long Code

The term long code and short code refers to the phone numbers that get used for sending the marketing message, along with the system used to send them. A long code message will get sent by a 10-digit number, which makes it appear as if the message is coming from a person. However, a long code system can only send one message per second, which means sending a large number of text messages, or messages with a high word count can be a timely process. Long Code messages are also restricted to SMS messages, so a long message can’t get converted to MMS.

Short Code

Short code is more suitable for business as thousands of messages can get sent at once, eliminating the issue of a word count. Short code messages also allow MMS messages. A short code uses a 5-6-digit number and comes in two variants.

●      Shared Short Code – A shared short code number is a single number used by multiple businesses at once, so cheaper than the next alternative. Consumers differentiate companies with the use of a specific keyword related to the company.

●      Dedicated Short Code – A dedicated short code is a number that only a single business can use. This code can get randomly generated or get chosen by the company employing the service. Though more expensive than the alternative, there are more options for customization, which is always a good thing in marketing.

Further Reading: The Bane of a Company’s Marketing Strategy

Character Limits In Other Messaging Mediums

Character limits in the medium of an SMS message, though manageable, can be seen as an inconvenience. However, they are not the only messaging platform to feature character limits.


The OTT messaging service by Apple, like other internet instant messaging services, does not come with a character limit. A user can send a message using iMessage, to another iMessage user, with as many characters as they wish. However, iMessage is also an SMS service, so if an iPhone user wants to send a message to another cellphone, that is not an Apple product, then the message gets converted to SMS. The 160-character limit applies to that converted message. Additionally, because iMessage is an internet-based service, if there is no Wi-Fi or data, then even if the message is to another Apple cell phone or tablet, it will still be an SMS message.


Though not a messaging service, Twitter can be a medium for delivering short messages. The social media posts or a Tweet gets restricted to a character limit of 280, which is an increase on the original 140-character limit. However, despite the new higher word count, many users of the platform do keep their posts within the initial 140-character limit.  It is enough characters to deliver a short message, whether a user is posing a question or making a statement, so users have felt no need to increase their message length.

Perhaps an SMS Character Length Limit Is Not All Bad

Whether for relaying a marketing message about a new product or texting someone to let them know that you are only five minutes away, the character limit of an SMS is not as detrimental as it might at first appear. A marketing message especially should be short and impacting, especially in today’s world, where everyone is always on the move. A marketing team can type out a message that will catch the recipient’s attention, and then send it en mass via their messaging app, which has a much broader reach than other alternatives. The fact that an SMS message goes straight to the recipient’s mobile device that is in the hands of the user on an average of 3 hours a day can be worth the lack of character allowance.

There are other marketing means for sending more lengthy pieces of text to avoid sending multiple SMS messages, such as email. However, these long posts are more suitable for someone who has an invested interest in a company. It will take time for someone to read through a long marketing post and that is if they see the email at all.

As Friedhelm Hillebrand devises from his research, 140 to 160 characters in a text message are enough to relay most messages.

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