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From SMS to RCS – A guide to next-generation mobile communication

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RCS Business Messaging Compared to SMS

Under the last few decades, text messages have been the the unparalleled backbone of digital communication. Its simplicity and near 100-percent range has always been its strength. But as users'expectations change, plain text is not always enough. Here comes RCS (Rich Communication Services) in the picture – an upgrade that transforms messaging app to an interactive platform.

But how does it work technically, and how can I ensure my message reaches markets that haven't fully rolled out RCS support yet? We'll clarify the concepts.

What is RCS and Universal Profile?

RCS is often described as ”SMS 2.0,”,
but it is technically a more comprehensive architecture. For messages to
look the same regardless of operator or phone model, the industry organization
GSMA has developed the Universal Profile (UP).

  • Universal ProfileA common technical standard that ensures features like high-resolution images, read receipts, and group chats work seamlessly across different networks.

  • Status 2026: While RCS is the global standard, the market is still in a transition phase. In Sweden, this practically means that Android devices have full support for RCS, while iPhone users on Swedish networks currently receive communication via SMS.

A2P and MaaP: When Businesses Talk to Customers

In the communications industry, we distinguish between person-to-person (P2P) chat and application-to-person (A2P) business messages. For RCS, the term Messaging as a Platform (MaaP) is used.

Through an API that handles MaaP, companies can go beyond just text and use:

  1. Rika Payloads: Instead of a simple link, we can send complex JSON structures that render as interactive carousels or buttons directly in the phone's messaging app.

  2. Verified identity: Unlike SMS, where the sender is often a hidden number or name (which can be hijacked), RCS offers a verified profile. Customers see the company's logo, brand colors, and a verification icon, increasing both trust and engagement.

Can I use RCS today?

Yes, absolutely! Technical advancements continue with more and more carriers adding support for RCS worldwide. When it comes to Swedish carriers, full support for RCS on Android devices is already available today. With the launch of end-to-end encryption between Android and iOS devices in iOS version 26.5 for private users, there are also clear signs that the world is ripe for a new modern messaging standard.

How do I reach a recipient whose phone does not support RCS?

When you send a message via our APIs, you can use the capability check endpoint, which in turn responds with a status indicating whether the device you want to send to supports RCS or not. With the help of this status, you can later implement a fallback that sends SMS to devices that do not yet support RCS technology.

  1. Capability Check: The system makes a quick request to see if the recipient's phone and carrier have an active RCS connection.
  2. Smart Routing: If the recipient has an active RCS profile (e.g., an Android user on a supported network), the interactive message with images and buttons will be delivered.
  3. Fallback to SMS: If the recipient cannot receive RCS (e.g., an iPhone user in Sweden or someone with temporarily poor data coverage), the message will be rerouted to our SMS API and sent as a regular text message. This ensures the communication chain is never broken.

Code Example: Send RCS with SMS Fallback

🔷
RCS with SMS Fallback - Transactional (C#) 
using System.Net.Http.Json;

var apiKey = "YOUR_API_KEY";
var rcsUrl = "https://api.ip1.net/v3";
var smsUrl = "https://api.ip1sms.com/v2";

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("Authorization", "Bearer {apiKey}");

async Task SendTransactionalMessage(string number, string text)
{
    var recipients = new[] { number };

    try
    {
        // 1. Capability Check for the specific number
        var cap = await client.GetFromJsonAsync("{rcsUrl}/phones/{number}/capabilities");

        if (cap?.capable == true)
        {
            // 2. Send transactional RCS
            var response = await client.PostAsJsonAsync($"{rcsUrl}/bundles", new
            {
                brand = "my-store-inc",
                agent = "YOUR_AGENT_ID",
                content = text,
                recipients = recipients
            });

            if (response.IsSuccessStatusCode) return;
        }
    }
    catch
    {
        // Log the error internally but proceed to SMS fallback
    }

    // 3. Fallback to SMS
    await client.PostAsJsonAsync($"{smsUrl}/messages", new
    {
        sender = "Verify",
        body = text,
        recipients = recipients
    });
}

public record CapResponse(bool capable);

// Example call:
await SendTransactionalMessage("46700123456", "Your code is: 123456. Valid for 10 minutes.");;
📄
RCS with SMS Fallback - Multiple (C#) 
using System.Net.Http.Json;

var apiKey = "YOUR_API_KEY";
var rcsUrl = "https://api.ip1.net/v3";
var smsUrl = "https://api.ip1sms.com/v2";

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("Authorization", "Bearer {apiKey}");

async Task SendSmartMessages(string[] recipients, string text)
{
    var rcsRecipients = new List();
    var smsRecipients = new List();

    // 1. Loop through and sort recipients based on capability
    foreach (var number in recipients)
    {
        try
        {
            var cap = await client.GetFromJsonAsync("{rcsUrl}/phones/{number}/capabilities");
            
            if (cap?.capable == true)
                rcsRecipients.Add(number);
            else
                smsRecipients.Add(number);
        }
        catch
        {
            smsRecipients.Add(number);
        }
    }

    // 2. Send RCS to everyone who can receive it
    if (rcsRecipients.Any())
    {
        var rcsResponse = await client.PostAsJsonAsync($"{rcsUrl}/bundles", new
        {
            brand = "my-store-inc",
            agent = "YOUR_AGENT_ID",
            content = text,
            recipients = rcsRecipients.ToArray()
        });
    }

    // 3. Send SMS to the rest
    if (smsRecipients.Any())
    {
    var smsResponse = await client.PostAsJsonAsync($"{smsUrl}/messages", new
    {
        sender = "MyCompany",
        body = text,
        recipients = smsRecipients.ToArray()
    });
}

public record CapResponse(bool capable);

var myNumbers = new[] { "46700123456", "46700987654", "456189040623" };
await SendSmartMessages(myNumbers, "Hello! This is a smart message.");;

Summary

Future-proofing your communication means preparing for the interactive future without losing today's reach. By understanding the interplay of RCS technology's capabilities and utilizing the reach of the SMS protocol until full market support is available, companies can build a stable and modern customer dialogue that works for everyone – regardless of the phone they have in their pocket.

Do you want to learn more about how your business can benefit from the MaaP architecture? By starting to build with RCS support today, you'll be ready when the market reaches full maturity, while a fallback logic ensures your messages always get through now.

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