How to choose the developer SMS API: A guide for developers 

Posted on September 5, 2022

With an open rate of 82%, SMS remains one of the best ways to communicate with customers. Building this functionality into your company’s app or platform without help is no easy task. But a properly designed API from a reputable company can simplify the process dramatically. In this post, we’ll discuss how your company can decide upon the best SMS API for its needs. 

The importance of finding the best SMS API

Some developers may decide to implement SMS messaging entirely on their own. They quickly realize that this is not the best-case scenario. In addition to the time and expense of building this functionality from scratch, there are other issues of practicality. Homegrown SMS systems often find themselves with limited send limits and spotty reliability. Worse, a poorly coded SMS system can be easily hijacked by scammers, putting the reputation of your company on the line.  

These are obviously undesirable outcomes. However, picking the wrong SMS API provider can often lead to many of the same headaches. When searching for the best SMS API for your company, it’s important to look for providers that are experienced in the telecom field and who have carrier-grade capabilities. 

Qualities to look for in an SMS API provider

The first thing to do when picking the best SMS API to use in your software project is to narrow down the list of potential providers that you’ll go with. At this point, you’re looking for broad qualities of the potential providers. Once you’ve narrowed down your selection to a shortlist, you can begin to sort through the specifics of what each provider offers in order to pick the one that best matches your needs. 


We’ve talked about how poorly implemented SMS can be hijacked by spammers. That doesn’t apply only to homegrown systems. Cheaper and less reliable providers are also prone to security problems. When looking for the best SMS provider, be sure to look at how each potential candidate approaches the concept of security. 


Having a reliable network is always important when you want to communicate with your customers. One of the big advantages of SMS is its near-instant delivery. Sometimes, it’s even more important that the message gets there on time. Imagine sending a verification code to a customer and telling them it will be there in a few moments, only to have them waiting much longer because you’ve chosen an unreliable provider.

Large network

In our connected society, your customer base is likely located around the globe. Limiting your ability to connect with them because of a provider that doesn’t have a large enough network to reach your customers where they are can be a major blow to your communication efforts. You should only consider providers that can guarantee delivery to a wide network area.


Not everything goes smoothly all the time. Whether you’re having difficulties implementing the API or something goes wrong with the service after it’s been implemented, you need to make sure the partner you’ve chosen to provide you with SMS services is there to support you. Pick a provider that makes customer support a priority so your own customers aren’t left waiting. 

Usage terms

Ideally, you’ll be able to test the functionality of your chosen provider before making a commitment. The best SMS API providers aren’t afraid to let you kick the tires before making a decision. Avoid companies that require you to commit to a lengthy subscription service. A good provider will allow you to pay on a metered basis. By only paying for what you use, you can affordably test the APIs and functionality of several providers before deciding on the one you’ll go with. 

Features to keep in mind when selecting an SMS API provider

Once you’ve narrowed down your list of providers, it’s time to start focusing more closely on how the specific features each offer fit in with your business goals. Once this process is completed, the choice for the best SMS API should be much clearer. You know your own requirements better than anyone, but here are a few suggestions of what to look out for:

Other services they offer

Often, the ability to send SMS messages doesn’t cover the entire range of telecom services your software may need to integrate. If this is the case, you’ll want to look at which other services are available from your chosen provider. This may include:

  • MMS – Perhaps the most obvious additional feature to go with SMS, MMS messages allow you to send more engaging content to your customers. Through the use of images, video, and audio, you can refine the type of content you send and do more through messaging than SMS alone allows for. Nearly every SMS provider should offer MMS services as well.
  • Phone numbers – The ability to choose your own phone number can provide a few benefits to businesses. You can choose to send communications to customers from a number that’s local to them to improve trust and build a sense of community. You can choose a toll-free number to reduce costs for customers on inbound calls. You can port existing numbers to the new platform or choose from available vanity numbers. Whichever need you have, make sure the provider you choose offers it.
  • Voice  – Modern digital systems combined with broadband allow companies to move beyond the traditional PBX system and take advantage of newer SIP trunking capabilities. If your company uses voice calling to communicate with customers, you may find the voice SIP offerings of many SMS API providers to be a useful addition.
  • Fax – Although faxing is becoming less common, it has still managed to transform itself for the digital age. Just as VoIP brings voice communications over the internet, the T-38 protocol brings faxing into the modern, internet-powered era. Fax over IP (FoIP) can bring new life to old technology and might be just the solution companies who still rely on fax need to revitalize their workflows.

Related: Making the move from PRI to SIP trunking 

Messaging capabilities

Of course, all of the additional features are pointless if your chosen API doesn’t do what you were originally looking for. When looking for an SMS solution, it’s important to know what options are available to you and how each potential API fits into those needs. Traditional long codes are simply the 10-digit local phone numbers that get assigned to everyone with a phone. Every SMS messaging API will support these. 

Here are some additional messaging options to look for:

  • Shortcode – Shortcodes are the traditional way that businesses had to send mass SMS messages. Carriers put a cap on how many messages can be sent through traditional long codes. These 5-digit shortcodes raise that limit significantly and make mass SMS possible. However, they are expensive and require a complicated approval process.
  • Toll-free – A toll-free number is also capable of sending mass SMS messages, though they also require an approval process. While you can send large amounts of messages through them, toll-free numbers can often seem impersonal. 
  • 10DLC Long code – The 10-digit long code is the industry solution to the expense of shortcode and the limitation of traditional local long code numbers. This more affordable option allows you to send mass SMS messages with a more affordable and less complicated solution.


When messages don’t get where they’re supposed to go when they’re supposed to get there, it frustrates both you and the customer. The ability to quickly identify and diagnose the problem is paramount to the success of your messaging campaigns. The best SMS API providers will give you the tools you need to troubleshoot message errors and check delivery receipts to ensure your messages are delivered in a timely fashion. 


When you’re adding SMS to your software, you want the process to be as easy as possible. One of the big benefits of using a third-party API is that it takes a significant amount of work off of your development team. Even poorly designed APIs will be much easier to implement than creating your own SMS system from scratch. However, poorly designed APIs are still a pain to work with. 

As we mentioned earlier, good providers will allow you to use their API without committing to a lengthy or expensive payment contract. It’s a good idea to try out multiple APIs to see which is the best fit for how your team works and what you want to do. 

Related: Getting to know Flowroute APIs

Let Flowroute help

Flowroute’s APIs were built with developers in mind. They are designed to make integration into your software as simple as possible. More importantly, we are experts in the telecom field. Our HyperNetwork meshes multiple networks into a single powerful telecom solution, ensuring maximum reliability for your communication needs. Find out more about how Flowroute’s SMS APIs can improve your company’s customer reach.

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