This article outlines the regulatory and platform requirements for sending messages to Singapore. These requirements are mandatory and apply to all customers sending Singapore traffic.
Important: Failure to meet these requirements will result in Singapore traffic being rejected or blocked. If you need assistance with migration or technical updates, please contact customer success team.
Overview
The Infocomm Media Development Authority (IMDA) has introduced new regulatory requirements for sending messages to recipients in Singapore.
To ensure compliance with these requirements, we are implementing the following changes to our platform.
Effective 1 April 2026, to send messages to Singapore, you must:
- Have a registered Singapore Sender ID on your account
- For API customers:
- Use the Sinch MessageMedia REST API
- Support TLS 1.3 security
- Send all traffic over HTTPS
Traffic that does not meet these requirements will be rejected or blocked.
These changes are mandated by the Singapore government regulator, IMDA, and are non negotiable.
Legacy Brand API requirements
API customers using any of the following must migrate to the Sinch MessageMedia REST API:
- DirectSMS API
- MessageMedia SMPP API
- MessageNet API
- Mobipost API
- SMS Central API
- Street Data API
Singapore traffic from these APIs will be blocked. If you need assistance with migration, please contact customer success team.
Sinch MessageMedia API requirements
Non REST API users
Customers using legacy APIs, including:
- SOAP
- M4UD
- SMPP
must migrate to the MessageMedia REST API to continue sending to Singapore. Singapore traffic through legacy APIs will be blocked.
REST API users
If you are already using the MessageMedia REST API:
- Your integration must support TLS 1.3.
- Requests using TLS 1.2 or lower will be rejected.
- All traffic must be sent over HTTPS. HTTP endpoints are not supported.
Sender ID requirements
All Singapore Sender IDs must be registered before messages can be delivered.
Ensure that every Sender ID used for Singapore traffic is registered on your account. For more information, see the Singapore sending requirements FAQs.
What you need to do
If you plan to send messages to Singapore:
- Register all Singapore Sender IDs. For more information, see the Singapore sending requirements FAQs.
- Migrate to the MessageMedia REST API if you are using a legacy API.
- Ensure your integration supports TLS 1.3.
- Confirm all traffic is sent over HTTPS.
How do I check if I’m already compliant?
Your IT team can:
Confirming API requests are made to an https:// endpoint
Checking server or application TLS settings to ensure TLS 1.3 is enabled
Reviewing connection logs to confirm that the negotiated protocol is TLS 1.3
Using standard TLS testing tools (e.g. command-line OpenSSL checks or online SSL testers) to validate the protocol version being used
If you're unsure, your IT provider or engineering team should be able to confirm this quickly.
How to Use REST API?
Current API users need to set up a REST API key, which can be done by logging in to the platform and navigating to Settings > API Settings > Basic Authentication > Create new Basic API key. If this navigation pathway is not available, please reach our Support team.
Rest API developer’s guide can be accessed from Sinch MessageMedia Developer Guides – Sinch MessageMedia.