SMS Long vs SMS Short Codes – What is the Difference?


SMS long and short codes serve very different purposes and it’s important you recognize what they’re good for. This will compare SMS long vs SMS short codes so that you know which is right for your marketing campaign and business needs.

What are Long and Short Codes?

You should understand what long and short codes are. As the name implies, one code is longer and uses more numbers while another is shorter. SMS long codes are essentially the same as phone numbers. They are 10 digits long and tied to an area code. SMS short codes don’t have an area code and are five or six digits long.

That may not seem to be a big deal, but you’ll see that these function very differently.



If your goal is to send as many SMS messages as possible, then you need an sms short code service like that from CDYNE. Carriers limit how many messages you can send at once with both codes, but short codes allow you to send much more than long codes.

An SMS long code can only send one message per second. That sounds fast, but it’s really not when you need to send hundreds or thousands of messages. SMS short codes can usually send 40 messages per second, which allows you to reach your customers very quickly.

Inbound and Outbound Ratios

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Another consideration is inbound and outbound ratios. Most carriers require about one inbound message for every three outbound messages with SMS long codes. If you fall short of this, then there could be issues with sending messages in the future.

On the other hand, SMS short codes don’t have this restriction. You can send hundreds of messages even if only a few people reply. This makes it much easier to reach people without worrying about penalties or other issues.

Customer Replies


Customers can reply to both SMS short codes and long codes, but the way they can reply is different. Since SMS long codes are basically just phone numbers, customers can text or call back. That’s good because these are best used for personal, one-on-one messages from banks, delivery people, and airlines.

SMS short codes can’t be called, but customers can reply via text. You can even program certain replies, like telling them to reply with a certain word to opt-in for discounts. While they can’t call, the truth is that most people would rather reply to a text message with another text.

Alerts and Critical Messages


Sometimes you have a critical message you need to send. In this case, SMS short codes are the way to go. Long codes take far too long with their one-per-second limit. If you have a critical message that people need to see, then you need a short code.


While both SMS long and short codes have their place, short codes are faster, more reliable and can be sent to hundreds or thousands of people with ease. Be sure to consider this when marketing your business and reaching out to your customers.