Singapore | Sending requirements FAQs
This article outlines some FAQs relating to changes implemented in 2023 to the requirements for SMS sending in Singapore.
We recommend you check out the Frequently Asked Questions on the SGNIC’s website for information about the regime, cost, and registration requirements.
Important: Effective from 31 March 2026, Singapore messaging traffic will be blocked by default unless your account has a registered Singapore Sender ID.
Can Sinch register a Sender ID for me?
No. We're unable to complete this for our customers.
The regulations specify that the customers themselves need to apply for their own registered Sender ID(s). Once you’ve successfully registered your Sender ID(s), you’ll need to provide us with a Letter of Authorization – you can find a copy of the letter template below.
What is a Letter of Authorization?
An organization may authorize a representative like MessageMedia to send SMS with the organization's registered Sender ID on its behalf. For example, a marketing firm is appointed by an organization to run a marketing campaign for them. To authorize that marketing firm to send such SMS with the registered Sender ID on the organization's behalf, a Letter of Authorization (LOA) provided by the organization who registered that Sender ID is required.
You can download the LOA template for the representative below.
Does this affect international roaming?
The Sender ID Registry Regime applies to all organizations sending messages with Sender IDs to Singapore numbers from 30 January 2023. After that date, messages containing unregistered Sender ID(s) to Singapore numbers will be blocked.
Which participating aggregator do I need to specify when I register my Sender ID(s)?
You will need to select Sinch Singapore Pte Ltd as the participating aggregator.
What if I want to add more Sender IDs later?
If you decide to register additional Sender IDs, you will need to send us a revised Letter of Authorization. You can download the LOA template below.
What do I do if I no longer need to send messages to Singapore?
There are a couple of options for you:
1. Remove Singapore numbers from your contact lists.
2. You can contact our support team to have Singapore sending blocked on your account.
Alternatively, you could do nothing - just bear in mind that in the event that you do send any messages to Singapore (deliberately or otherwise), your messages will be blocked.
What happens if I don’t do anything?
If you haven’t contacted us to block Singapore, and you attempt to send messages with unregistered SenderIDs to Singapore, your messages will be blocked and charges may apply under your Customer Contract.