1. I do not quite understand your first sentence.
2. Let's see if they can offer a bit of free incoming voice roaming or not, like Zym 10 minutes per month RoamGuard. But if they can learn from eight, SIMBA and M1 Maxx to offer free incoming/outgoing roaming voice, that will be great.
3. High roaming Voice charge is one of the main pain point for Singtel MNO plans and MVNO plans like Zym, Zero1, VIVIFI and CMLink. Some users actually prefer Singtel Gomo and hi! by Singtel in this regard as you will not have bill shocks (no support of roaming voice calls).
4. Singtel MNO plans: pay-per-use roaming charges:
https://cdn2.singteldigital.com/con...-services/mobile/roaming/pdf/RoamingRates.pdf
5. Zym as a reference:
https://zym.sg/faq/roaming-calls-sms/
5.1) What are the roaming voice call rates?
Making/Receiving calls while overseas can be
VERY expensive, as we incur costs from the supplier and add a markup to cover our operational expenses. Therefore, we recommend utilizing alternative methods like messaging apps or Wi-Fi calling whenever possible.
However, if you do need to make such a roaming call, please check out the rates below.
If you are in Malaysia & Brunei:

Incoming call: $0.40 per min

Outgoing call within Malaysia & Brunei: $0.40 per min

Outgoing call to Singapore: $0.60 per min

Outgoing call to rest of the world: $7.00 per min
If you are in any countries outside of Singapore, except MY & Brunei:

Incoming call: $5.00 per min

Outgoing call within the same country: $5.00 per min

Outgoing call to SG: $7.00 per min

Outgoing call to rest of the world: $7.00 per min
5.2) What are the roaming voice call rates?
Making/
Receiving SMS messages while overseas can be
VERY expensive, as we incur costs from the supplier and add a markup to cover our operational expenses. Therefore, we recommend utilizing alternative methods like messaging apps or Wi-Fi calling whenever possible.
However, if you do need to make such roaming sms, please check out the rates below.
If you are in Malaysia & Brunei:

Incoming SMS - Not chargeable

Outgoing SMS - $0.40 per SMS
If you are in any countries outside of Singapore, except Malaysia & Brunei:

Incoming SMS - Not chargeable

Outgoing SMS: $1.00 per SMS
10. I am seeing a "Roam Guard 10 Mins" in my mobile app or bill invoice. What is this?
W.E.F Feb 2026, Roam Guard, a new feature, automatically absorbs the cost of your first 10 minutes of incoming roaming calls each month while you’re overseas to help prevent bill shock; any incoming time beyond 10 minutes and all outgoing roaming calls are charged at standard pay‑per‑use roaming rates.
W.E.F Feb 2026, Roam Guard, a new feature, automatically absorbs the cost of your first 10 minutes of incoming roaming calls each month while you’re overseas to help prevent bill shock; any incoming time beyond 10 minutes and all outgoing roaming calls are charged at standard pay‑per‑use roaming rates.