Getting Started

What do I need to register for U.S. Cellular® Developer Portal?

Registration is really simple. Basically all you need is a valid email address and a decent password. 

How much does it cost to join?

U.S. Cellular® Developer Portal is FREE to join! There is no cost to join the program and become a member of the community. You can also register a developer account and create projects in a sandbox environment for free. Register Now!

Why do I need to create a 'Developer' account?

Once you have created a user account on U.S. Cellular® Developer Portal, you will need to create a developer profile so you can then create projects and receive the credentials for your APIs.

Can I have more than one 'Developer' account?

Yes, after you create your profile, you can create multiple developer profiles that are associated with your profile. This will allow you to segment different groups of projects for various purposes. Most users will have no specific need to create more than one 'developer' profile but if you have that need you can do it. Keep in mind that each developer profile will establish a separate business relationship with U.S. Cellular®.

Creating A Project

How do I create a project?

Once you have created a Developer profile you need to create a project so you can receive your credentials for using the APIs. This is a straightforward process. In your Developer profile, simply click on Create a Project and complete the required details.

Can I have more than one project?

YES! We encourage you to develop projects and promote them to production. You can create projects under your developer profile. When you create a new project it will be in 'Sandbox' status.


What does it mean to have my project in 'Sandbox' status?

When you create a project it will be in 'Sandbox' status. This will give you very restrictive and limited access to endpoints while you are developing your application or service. You will have a maximum of 100 live transactions in the sandbox. These sandbox transactions are a finite and precious resource for you as a developer so be sure to use them carefully.

Can I use the same endpoints for multiple projects?

No, the Terms and Conditions of use restrict the use of endpoint credentials to a single project. This is to isolate your projects from each other. If you have a project that is mis-behaving or needs to be isolated for whatever reason, we can easily suspend the specific endpoints in use based on credentials associated with your project until you resolve the issue. If you reuse these endpoints across multiple projects, shutting down the endpoint would affect ALL projects that were using that endpoint.  It only takes a minute to create a new project and it's easy and free.

Is there a prescribed architecture for building applications that use U.S. Cellular® Developer Program API's?

Yes, there is a prescribed architecture for using the APIs. Basically, it is a client/server architecture that requires that your service have a server to act as the single connection point to the API interface. If you have mobile or desktop clients, they must communicate to your server and allow the server to invoke API calls and pass the response back to the client.  Mobile or Desktop clients must not call the APIs directly.

Why do I need to use a proxy server for my applications?

There are a couple of reasons. First, we want to ensure that we don’t have several hundred clients calling the API directly using your credentials. This poses a security risk to your service and could negatively impact your revenue stream or your billable activity.  Second, there is business logic that is required for these services to really shine. Things such as managing users privacy permissions or doing informed consent for purchase. These cannot be done if there is no server.

Who do I contact if I have a question about U.S. Cellular® Developer Program?

Try posting your question on the Forums. Moderators review the forums regularly and will be able to respond there for the benefit of all. This is the preferred method as everyone can benefit from your question and the answer.
If you have a question of a more personal nature and don't want to expose yourself to everyone, send your inquiry via our Contact Us form. We'll get back to you as soon as we can.


What SMS Features are supported? Are we restricted to only short code sender names or can it be alphanumeric or long numbers?

U.S. Cellular supports the oneAPI v2.0 SMS REST. Long numbers are supported, however, this requires additonal network testing. We strongly encourage use of short codes whenever possible.

Do you support delivery reports?

Yes. Delivery reports are sent to the developer.


The following methods are available:

Sending SMS:

  •  Send an SMS from Your Application
  • Query the Delivery Status of an SMS  
  •  Notify Client About Message Delivery Status  

Receiving SMS:

  •  Retrieve SMS Sent to your Application (which is identified by registrationId) 
  •  Notify Client about Message Arrival 


Is MMS supported?

Yes. Developers can enable MMS in their apps using our MMS API. Please see our Resource page for further details.

Payment API

Mandate Termination-notification of when a service is cancelled. Who is responsible for triggering the mandate cancellation via the carrier billing API?

U.S. Cellular. (note: this is not mandatory to configure). It is up to the developer on whether or not they want to receive mandate termination notifications.

If someone leaves U.S. Cellular® as a customer and they're subscribed to an application/product/service via the carrier billing API, how does the partner know that the customer has left?

When we notify our billing partner that the MDN has been cancelled, they then terminate everything on their end. The billing partner also sends a notification to the developer (only those that the end user was subscribed to) to advise them of the termination.

How do billing cycles work for the Payment API?

The initiation date is the anniversary (renewal) date.

Can a subscription be pro-rated based on the initiation date? If not, are billing settlement dates variable?

No. The platform is not capable of handling pro-ration. However, pro-ration is not needed since the initiation date is the anniversary (renewal) date. As a result, billing settlement dates are not variable.

Can I offer users a free month of a subscription and initiate payment after the free trial runs out?

Yes. There are different ways of doing this. The most common way is to use a vendor-managed logic.