MVNO zero1 seems to have activated Voice roaming for both $9.90 and $29.90 plans. Users can try out if voice and sms roaming works if you travel across the causeway.
For earlier adopters of the old plan S$29.90 (discounted at S$19.90), the service will be activated in November. A new SIM card will be issued and subscribers will need to collect it at their office.
No details of roaming charges and data roaming are available.