Singapore voice guidelines
Voice calling guidelines for Singapore (SG), covering reachability, caller ID formats, DTMF support, and emergency services.
Locale overview
| Field | Value |
|---|---|
| Country | Singapore |
| ISO code | SG |
| Region | Asia-Pacific |
| Dialing code | +65 |
Reachability
| Call type | Supported | Notes |
|---|---|---|
| Domestic inbound | Yes | — |
| Domestic outbound | Yes | Caller ID must be a Singapore number; see restrictions below |
| International inbound | Yes | — |
| International outbound | Yes | — |
| Toll-free inbound | N/A | — |
| Toll-free outbound | No | Not supported |
Outbound caller ID restriction
For outbound calls from Singapore to domestic destinations, the caller ID must be a Singapore phone number. Non-local numbers are not accepted as caller ID due to IMDA (Infocomm Media Development Authority) regulatory measures against spoofed calls, which took effect in 2020.
Numbers with a Level 3 designation display in E.164 format unless the registered address is within Singapore.
Caller ID
| Call type | Format |
|---|---|
| Domestic inbound | +E.164 |
| Domestic outbound | +E.164 |
| International inbound | +E.164 (non-guaranteed) |
| International outbound | +E.164 |
DTMF support
DTMF is supported using RFC 2833 format for both inbound and outbound calls.
Emergency services
Emergency services calling is not supported for voice calls in Singapore.
Compliance note
These guidelines summarize carrier requirements at the time of publication and do not constitute legal counsel. Verify that your implementation complies with all applicable telecommunications regulations in Singapore.