Global Reach With Our Powerful SMS APIs

Don’t like to settle? Neither do we. That is why we offer you global SMS APIs with easy integration and high operational stability. All while still being one of the best priced SMS suppliers on the market. By integrating with GatewayAPI, you unlock powerful communication capabilities – even within your own service.

What do you need?

Choose the SMS API that fits your needs

REST API (most commonly used)

The REST SMS API is available for and based predominantly on HTTP POST calls and JSON. The API offers a range of functionalities, including Sender Class specifications, overcharged messages, webhooks and number lookup. This API is used by most of our customers and provides an easy and familiar way to submit SMS messages to our systems.


Short Message Peer to Peer (SMPP) is a robust, stateful TCP protocol built for asynchronous communication between clients and servers and is great for handling huge volumes of SMS messages. Unless you’re managing your own SMS gateway, the benefits of connecting via SMPP might be minimal. In many instances we suggest exploring our REST API.

Kannel API

Kannel is one of the most popular open source SMS gateways out there. One of the reasons for its popularity is its ability to provide a gateway between complicated and wildly different APIs used by the mobile networks such as Nokia CIMD, CMG UCP/EMI, SMPPC combined with a super simple HTTP interface for the developer. Our Kannel API is fully featured and supports URLs, all encodings, scheduling, expiration etc.

Simple SMS API

The Simple SMS API is well-suited for those that have a system where JSON is not an option – although the API is able to parse requests coming in as either JSON, Form-encoded or even as a querystring. However, some caution must be taken when building a form/querystring request with this API, especially when it comes to lists, as each list needs an index.

Keyword API

Keywords are essential to campaigns, donations, competitions and two-way communication. Our Keyword API enables you to add as well as remove keywords to your account programmatically, supporting your use of value-added services (VAS). Please note that accessing this API necessitates a distinct agreement with GatewayAPI. This is specifically designed for resellers or accounts that have extensive requirements for two-way messaging.

Our fantastic customers

Trusted by 50,000+ organizations worldwide


We have over 50,000 satisfied customers worldwide

Over 2.5bn

SMS messages delivered to date


SMS messages delivered yearly

ISAE 3000

Completely GDPR-proof with ISAE 3000 certification from BDO


Choose between thousands of integration-options

A wide array of options

Choose your preferred integration method

We have made it incredibly easy to connect your system with our APIs. You can choose the coding language that is best suited to your needs, which means that whether it is a solution in Java, C#, PHP, Python, Node.js etc. you are working with, you can easily integrate with us. Furthermore, our documentation is detailed and has many examples included. 

You also have the option of using the automation platforms Zapier, Make, Flowize or IFTTT to integrate your system with our SMS API.

Use with caution

Powerful tool to get attention

SMS messages have an unmatched ability to capture the attention of the recipients. That also means that there are a number of best practices that need to be followed in order to maximize the effectiveness of the SMS broadcasts.

In addition, it is essential that users’ personal data is processed in accordance with regulations in your area.
It must also be clearly communicated how the user can unsubscribe, for example “Send STOP to 1234 to unsubscribe”.

It is important that:

The relevancy of the message is high

The frequency matches the needs of the target audience

The frequency matches the needs of the target audience

You don’t broadcast the campaigns too early or too late. The rule of thumb is between 7am to 8pm.

SaaS companies, charities, consultants etc…

Read about how different businesses have benefited from using our SMS APIs

Streamlining customer communication for enhanced convenience

NEMADVOKAT, translating to EASYLAWYER, prides itself as Denmark's premier digital law firm. Their innovative approach is geared towards digitizing their legal advisory services to a maximum extent. Consequently, a range of procedures, including consultations, document handling, and signings, are proficiently managed via their digital platform, which also keeps expenses down.

NEMADVOKAT employs SMS messages to warmly welcome new clients, securely send passwords and promptly notify customers when their documents are ready for digital signature.

To date, NEMADVOKAT has successfully facilitated SMS communication with tens of thousands clients. Their broad range of services includes transactions related to property buying and selling, company startups, trademark infringement and beyond.

Leveraging SMS for charitable contributions: Danish Red Cross' approach

The Danish Red Cross has embraced the GatewayAPI platform to drive their SMS campaigns and manage SMS-based donations across Denmark. A direct connection is used to ensure a smooth execution when large campaigns with millions of recipients are broadcasted. 

For donations, The Danish Red Cross employs a dual strategy that includes the Premium Message Class and their unique short code (1290). This short code is linked to various keywords that are each associated with different fundraising campaigns.

Whenever a mobile user sends an SMS to the Danish Red Cross using a specific campaign-related keyword, a predetermined amount is instantly debited from the user’s mobile account. This streamlined process makes donating quick and effortless for the user.

Beyond immediate monetary benefits, these mobile donations also serve a strategic role in generating leads. The data gathered through this process can be leveraged to convert occasional donors into sustained supporters, further strengthening the Red Cross’ humanitarian endeavors.

Encrypted SMS messages: A key component in Realkreditkonsulenterne's online service

Realkreditkonsulenterne, an online service that simplifies the process of managing mortgage loans for its customers. By simply inputting their addresses, customers can gain insights on whether they should restructure their loans, switch banks or negotiate lower interest rates.

Martin Riedel, the owner of Realkreditkonsulenterne, emphasizes the importance of secure communication, especially considering the sensitive nature of the information they handle. “We needed an SMS API that ensured robust security. The anonymized flows in the Premium Message Class fit perfectly with our stringent security requirements,” Riedel explains.

Not only does the use of SMS via the Premium Message Class address security concerns, but it also reduces the need to invest in building an app to handle customer communication. Instead, once customers sign up for the service, they can choose to receive SMS messages instead of e.g. app push notifications.

“SMS messages have an incredible impact. They are typically read immediately as well as prompt action from the recipients”, Riedel notes.

Streamlining user communication via our SMS API

Minuba is a platform dedicated to optimizing and streamlining operations for businesses in the installation and construction sector.

By integrating with GatewayAPI, Minuba enables its users to efficiently communicate with their customers using the Standard Message Class, offering multiple benefits:

  1. Keeping customers updated on service calls: Customers receive timely notifications about scheduled service calls, ensuring they are well-informed and prepared.
  2. Allowing customer feedback: If a service call time doesn’t suit a customer, they can conveniently communicate this back through the system, ensuring mutual convenience.
  3. Sending advance reminders: Customers receive reminders a few days ahead of the scheduled service, thereby reducing the chances of missed appointments.

Crucially, these SMS messages are automatically generated and tailored with all relevant details such as the customer’s name, case number, as well as the date and time of the service. This approach not only simplifies communication but also fosters a more personalized and efficient customer experience.


Do you seek a provider you can trust completely?

We offer complete transparency, whether you want to see our prices, track our sky-high uptime, see contact details of our team members or get in touch with our support team.

Moreover, we offer full GDPR compliance, which undergoes an annual ISAE 3000 audit.

We expedite SMS messages through our direct connections worldwide, ensuring your messages reach their destination in the shortest time frame possible. Our real-time delivery reports clearly indicate which messages have been successfully delivered enabling you to keep your recipient list updated as well as conduct investigations based on our detailed error codes.

Don’t like to settle? Use GatewayAPI

Get access to high quality SMS connections in over 200 countries