Basic SMS API Knowledge
More companies than ever before are leveraging the power of SMS to boost their texting campaigns and better connect
with customers. But before you sign up with an SMS API, it’s important to learn how to use this tool so that it works
effectively for your company.
There are several basic components to an SMS API. These include keywords, short codes and long codes, 10DLC, and
toll-free numbers. Learning how SMS APIs work, such as the function of an SMS gateway, and what capabilities SMS APIs
include, such as MMS messaging, is also important.
Learning about SMS APIs equips you with the knowledge you need to decide whether or not an SMS provider is the best
fit for your company.
SMS API Rundown
SMS messaging is one of the most effective ways to connect with customers, no matter what industry you’re in or what
type of audience you serve. It’s more efficient and convenient than other methods, such as email or voicemail
campaigns, in addition to being the preferred communication medium of most customers.
But if you’re interested in utilizing this medium to boost your business, there are a few key pieces of information
you’ll need to know first.
What Is An SMS Keyword?
SMS keywords are specific words or phrases that users can text to your company’s short code or long code which trigger
an automatic response. Keywords can be used for a variety of reasons, but are most often used for marketing or
campaign subscription purposes.
For example, a user can text JOIN to your short or long code in order to become a subscriber and receive your texts.
Alternatively, they could text a keyword to join a contest, pledge support, learn more, or one of a million other
Below are best practices and tips for using SMS keywords.
Keep It Simple
The best SMS keywords and simple SMS keywords. When keywords are simple, users are more likely to remember them and
less likely to accidentally misspell them. Additionally, simple keywords are less likely to be autocorrected.
For example, keywords like MORE or CONTEST are simple and easy for users to type, which makes them ideal.
Make It Unique
While still keeping them simple, try to make your SMS keywords unique so that users won’t have trouble remembering
them. Keywords that are less common are more likely to stand out.
It can be tricky to walk the line between making your keywords unique and making them too complicated. When in doubt,
err on the side of caution.
Avoid Special Characters
SMS keywords shouldn’t have special characters in them. Characters change depending on the type of phone a user has
(smartphone or cell phone) and what operating system or keyboards they use. Characters can also change according to
language. Because of these reasons, it’s best to exclude special characters from your keywords.
One Word Is The Best Option
For the best results, limit your SMS keywords to one word. Just like ensuring your keywords are simple, this makes
them easier to remember and easier to spell. Each letter or word you add is a new opportunity for users to misspell
or the phone to autocorrect.
Try A/B Split Testing
SMS keywords A/B testing, also known as split testing, is a randomized experiment where users receive one of two (or
more) possible versions of a keyword. Whichever version of the keyword yields the best results is the one companies
move forward with.
What Is An SMS Short Code?
SMS short codes are unique 5 – 6 digit phone numbers from which you can send and receive SMS and MMS messages. They
can handle both high- and low-volume texting, but are ideally suited for mass texting and application-to-person
. This makes them perfect for companies looking to stand out and quickly connect with large numbers of
SMS short codes have a wide variety of uses, from marketing and promotions to reminders and alerts to authentication
and password resets and more. They’re used across nearly every industry, from retail to debt collection and many
There are two different types of short codes: dedicated short codes and shared short codes. Dedicated short codes are
further broken down into two categories: vanity and random codes. We’ll go more into detail about each of these below.
The Common Short Code Administration (CSCA) leases short codes for three, six, or twelve-month terms to companies who
have completed the short code provisioning process. This process can take anywhere from 4 – 8 weeks depending on the
If your company is interested in a short code, you’ll need to connect with a short code provider. The best API
companies will also offer SMS short code services and work on your behalf with the carriers to expediate your
application and the provisioning process so that you can begin using your short code as soon as possible.
Shared SMS Short Code
Also known as common short codes, shared short codes are codes used by multiple companies to send messages. Each
company has separate subscriber lists, but uses the same short code.
The main benefit of shared short codes is that they’re much more affordable than vanity short codes. Shared short
codes only cost roughly $500 - $1,000 per month, whereas vanity codes generally cost approximately $1,500 per month.
However, the main drawback is that there has been consistently high detections of spam with shared SMS short codes. As
a result, many short code services and API companies have stopped offering them. If you’re interested in using a shared
short code, check with the SMS API provider you’re interested in prior to signing up.
Dedicated SMS Short Code
Dedicated SMS short codes are numbers that are used exclusively by one company to send SMS messages. They can be used
to curate and emphasize brand identity, but are useful in general for mass texting.
They have lower spam rates than shared short codes, which make them the more reputable option as compared to shared
SMS short codes. You also get unlimited mobile keywords to boost your SMS text campaigns.
However, they are more expensive. Depending on whether you choose a random or vanity code, you can expect to pay
anywhere from $1,000 - $1,500 per month.
After you find the right shortcode service, there are two different types of dedicated short codes your company can
choose from: vanity codes and random codes. We’ll go into more detail below about each of them, their benefits, and
how to tell if they’re the right choice for your company.
SMS Vanity Code
Vanity codes are SMS short codes that are customizable according to company specifications. Companies can choose which
5 – 6 digits they want in their short code and in what order, provided that vanity code isn’t already being leased.
For example, if you have a company called 123 A/C & Heating, you could lease the short code 123-123. Vanity short
codes are generally more memorable than random codes because the numbers have meaning, such as being related to the
company or spelling out a certain word.
Because of this, they’re useful for brand marketing and increasing brand recognition.
SMS Random Code
Also known as non-vanity short codes, SMS random codes are short codes that are blindly (i.e., randomly) assigned to a
company by phone carriers after the company has completed the short code provisioning process.
With these types of short codes, companies have no control over the number they are assigned. Though these numbers are
not as useful for branding, they are much more affordable than vanity codes.
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What Is 10DLC?
10 Digit Long Code (10DLC) is the new standard for A2P text messaging using traditional long codes. 10DLC is a more
reliable messaging channel with varying levels of throughout, approved by the major carriers like AT&T, T-Mobile, and
Traditionally, long code texts sent at one message per second (MPS). With 10DLC, there will be improved throughput no
matter which throughput level your company is assigned.
You can apply for a 10DLC through the Campaign Registry (TCR). TCR is directed by a third-party company and works
directly with the mobile carriers. Not all mobile carriers have chosen to use TCR to administer registration on behalf
of their brand, but many major carriers are transitioning toward this.
SMS API companies and long code providers can register 10DLC on behalf of a company, but companies that support many
brands are encouraged to directly register with TCR. Applications are typically approved within 24 hours.
Companies are not required to register with TCR. However, messages from unregistered companies will be subject to more
rigorous filtering, higher carrier fees, and traffic suspension, effective October 1, 2021.
What Is An SMS Long Code?
SMS long codes are traditional 10-digit phone numbers that can send and receive SMS messages. Also known as commercial
long codes, these types of numbers are ideally suited for low-volume messaging and person-to-person communication (P2P).
Long codes can also send and receive text messages internationally.
They are preferred by small businesses because they are more affordable (as low as $1.00 per month) and create a more
personalized marketing experience. When you use a long code, users receive texts from numbers that look just like the
ones they use.
SMS API providers can typically process applications for long codes within a few hours, which means that you can apply
for a long code and send messages from it on the same day. This is yet another benefit of using an SMS long code.
What Is A Toll Free Number?
Toll-free numbers are long codes that appear as phone numbers from a large business. They’re primarily used for
application-to-person (A2P) messaging, but are prohibited from containing any promotional or marketing content.
Not all SMS API companies or long code providers offer these types of long codes. If you’re interested in using
toll-free numbers as part of your communication strategy, check with a provider to see if they offer these numbers
prior to signing up.
What Is An SMS Gateway?
When SMS APIs send messages, they’re directed through aggregators and then network carriers. And in order for network
carriers to connect to each other, they use Short Message Service Centers (SMSCs). In turn, SMSCs connect to each
other through SMS gateways.
That’s a long stream of connections, but each one is essential to the process. SMS gateways are especially crucial
because they translate the different “languages” (i.e., communication protocols) that SMSCs use. Without SMS gateways,
SMSCs wouldn’t be able to “talk” to each other and send messages.
It’s possible for companies to integrate an SMS gateway into their communication and marketing plan independently of
an SMS API. However, it’s more efficient to invest in an SMS API that dually serves as an SMS gateway— that is, an API
that also has all the functions of a gateway.
Before investing in an SMS API, check to see if it has gateway capabilities.
What Is MMS?
Whereas SMS messaging only allows for plain text and links, Multimedia Messaging Services (MMS) allows for pictures,
videos, .gifs, and other media content. It’s an expansion of the core SMS messaging protocol and allows companies to
more creatively connect with customers.
However, there are limitations to MMS that users should be aware of:
- Not all phones are equipped to receive MMS like they are to receive SMS, which potentially limits the amount of subscribers you can include in text campaigns
- Users need a data connection to communicate using MMS, which poses another limitation in terms of geographic location and subscribers
- MMS messages cam take longer to send depending on the content amount and size, which could potentially impact time-sensitive communication
Despite these limitations, MMS providers offer more options in terms of content for text campaigns. If your company is
looking for a way to give your SMS messages an extra edge, then MMS may be the way to go.
Most SMS APIs come equipped with a variety of features, including MMS capabilities. If you’re interested in sending
multimedia content, make sure the API provider you’re interested in also serves as an MMS provider.