What it means
The Do Not Call (DNC) Registry is part of Singapore's PDPA framework, run by the Personal Data Protection Commission (PDPC). Singapore residents can register their phone number to opt out of unsolicited marketing calls, SMS, and faxes. The DNC list expanded over time to cover voice, SMS, and fax-equivalent channels.
Businesses sending marketing messages must check the DNC Registry before sending, unless they have prior express consent from the recipient or fall under a narrow set of exceptions (existing ongoing relationship, etc.).
Why it matters
For Singapore-based WhatsApp marketing, DNC is one of the two big compliance gates (the other is opt-in). A business that sends marketing WhatsApps to a DNC-registered number without consent is in breach, with fines up to SGD 200,000 per case.
The practical effect: every WhatsApp marketing list for Singapore audiences has to be scrubbed against the DNC Registry before broadcast. Most BSPs and CRMs offer automated DNC scrubbing.
Example
A property developer plans a Singapore-wide broadcast to a 15,000-contact list bought from a third-party data vendor. Before sending, they run the list through the DNC Registry: 22 percent of numbers are registered. They drop those numbers, send only to the 78 percent remaining, and avoid a PDPA breach that would have cost them millions.