Channel Fallback & Routiing (2)

Every market in this compliance series allows URLs in SMS messages. Japan does not. Japan's major carriers commonly filter or block standard SMS containing URLs on many A2P routes as part of anti-phishing measures. A message with a link to a landing page, a ticket confirmation, a tracking update, or any other web address will generally not be delivered to Japanese recipients through standard SMS channels. This single restriction, with no equivalent in any other market covered in this series, reshapes every program that was designed anywhere else and then extended to Japan without adjustment.

Indonesia has one of the highest A2P SMS fraud rates in Southeast Asia. That is not a background detail. It is the reason why Kominfo, Indonesia's Ministry of Communication and Digital Affairs, works alongside the country's mobile operators to actively filter, block, and shut down traffic that does not run through approved channels. If your SMS program in Indonesia is delivering today but has not been registered properly, it is operating on borrowed time.

Most international teams configuring an SMS program for Mexico expect to register a sender name, just as they did in the UK, Australia, Nigeria, or Kenya. They go through the process, choose a branded sender ID, and get their first message out. The message arrives. The recipient sees a short code, not the brand name. In Mexico, this is not a deliverability problem. It is how the system works for everyone.

On July 10, 2025, Uganda's Personal Data Protection Office secured the country's first criminal conviction under the Data Protection and Privacy Act 2019. The case involved a digital lending company whose director had used a borrower's personal data, name, photograph, and phone number, to create a threatening video circulated on WhatsApp. The director was convicted for operating without PDPO registration and for processing personal data without consent. The fine was modest. The precedent is not. The PDPO's acting director was explicit: this conviction is the beginning of assertive enforcement, not an isolated case.

Your SMS program worked in testing. It worked for the first campaign. Then, somewhere between your platform's dashboard and your customers' phones, a growing share of messages started disappearing. No error. No bounce. Your dashboard says sent. Your customers say nothing arrived. If you are messaging into Nigeria, this is not a bug. It is the predictable result of a regulatory system that most teams only learn about after it has already cost them.

Brazil is simultaneously one of the most challenging markets to configure SMS for and one where SMS configuration is often not the right starting point. With approximately 148 million WhatsApp users, Brazil ranks second globally in WhatsApp adoption behind only India, and WhatsApp penetration sits at well over 90% of smartphone users. For many operational programs in Brazil, the channel architecture question comes before the SMS compliance question: which audience segment needs SMS, and which segment is better served through WhatsApp with SMS as the fallback?

Your SMS program is sending. Your platform dashboard shows messages delivered. And somewhere between your server and a Rogers or Bell subscriber's phone, a portion of that traffic is being filtered, throttled, or silently dropped because your number is unregistered A2P traffic on a domestic Canadian carrier.

The Information Regulator of South Africa has been explicit about what changed in 2024. For the first five years after POPIA came into force, the regulator's approach was education. That phase is over. In February 2024, the regulator issued its first enforcement notice for a direct marketing violation under POPIA. In December 2024, it published a Guidance Note spelling out exactly what Section 69 requires. In April 2025, it amended the POPIA Regulations to simplify how data subjects can object to marketing and request deletion of their data. The signal across all three actions is the same: enforcement has begun.

Tanzania has 90 million mobile subscriptions and one of the highest mobile money transaction rates in Sub-Saharan Africa. It is also a market where the Tanzania Communications Regulatory Authority has been tightening its grip on commercial SMS traffic since 2023, where every alphanumeric sender ID generally needs to be registered with the relevant mobile network operators before a single message is sent, and where a 2022 data protection law with active enforcement adds a second compliance layer that most operators building SMS programs have not fully accounted for.

Since January 1, 2023, commercial messaging platforms in France have not been permitted to send marketing SMS from numbers beginning with 06 or 07. Those are the standard French mobile number prefixes, the numbers that French recipients associate with calls and messages from real people. For commercial SMS, those numbers became unavailable to business platforms. Organizations that set up their French SMS program before that date and have not updated their routing since may be sending from numbers that are no longer permitted for commercial use.

Most teams designing SMS programs for Rwanda discover the two-way limitation after the program is already built. The workflow assumes recipients can reply to confirm, opt out, or respond to a survey. The sender ID is registered, the consent records are in order, and the first broadcast goes out. Then nothing comes back, because standard A2P SMS routes used by most providers do not support inbound replies on MTN Rwanda and Airtel Rwanda.