Using a SIP Trunk is the best option when considering numbers for your Yeastar Cloud PBX. It is also possible to retain your existing business number when switching over to SIP. This article briefly describes the porting process for a number from Singtel to Hoiio.

Upon completion of number porting, subscription charges for your phone number will be based on Hoiio’s rates:

  1. You will no longer be paying Singtel “Number Retention Services, Hunting Facility, Auxiliary Line, Exchange line”, as these items are related to RJ11 hardwires.
  2. Your existing PABX Server is no longer needed, and you will manage your phone system from the Yeastar web portal.
  3. Telephone cables from Singtel which connected your PABX server to your keyphones (RJ11), are no longer needed.
  4. Your existing keyphones are no longer needed. You can use an IP phone with an internet cable (RJ45), which can be installed anywhere. This makes it much more convenient when you have to shift your phone system to a different location.

*Note: Number porting from Singtel (PSTN/POTS/RJ11 or ISDN) to Hoiio Pte Ltd (SIP trunk) is essentially a Singtel to Singtel porting. As Hoiio’s backend is built on Singtel’s platform as well, all the numbers are ultimately owned by Singtel.

Number porting procedure (Initiated by client):

  1. Provide 3 months most recent Singtel phone bills to Hoiio Pte Ltd: Email to and CC to, stating that you intend to proceed with number porting)
  2. Get a written-confirmation from Singtel stating that there is no existing contract / additional services (eg. hunting line, auxiliary line…) / bundle (like TV, internet plan…) associated with the number that is going to be ported: Email to and forward Singtel’s reply to with in CC.

Sample Email Format to Singtel:

Subject: Checking contract for 65 XXXX XXXX

Dear Singtel,

Please assist to check and advise on below information:
1) Are the below number currently under contract, and are they allowed to be ported over to another Service Provider?
<<List of Numbers>>
2) Is there any other bundle service/facility under these numbers? If yes, I would like to terminate the bundle/hunting services and hunting number.

Best Regards,
<<Customer Name>>

Once it’s confirmed that there is no existing contract under Singtel, Hoiio’s Service Team will proceed to invoice the client for one-time porting fees (SGD 30/Number).

  1. Hoiio will estimate a porting date to the client (This is just a suggested date, the official date still needs to be confirmed by Singtel).

The below forms will need to be filled in by the Client and sent back to Hoiio at

  1. Application for Internal Number Portability (if porting from Singtel to Hoiio Pte Ltd)
  2. Fixed Number Port-In Request Form (If porting from a Non-Singtel provider to Hoiio Pte ltd)
  3. LOA (Letter Of Authorization)
  4. In case there are additional services tied to the number, please confirm you acknowledge that those lines will be terminated when the number is ported over.

Upon receiving a complete set of information, Hoiio will process the porting request with Singtel,  and inform the client via email a confirmed date and time for actual number porting to take place.

Important Points to Note:

  1. All required documents need to be submitted at least 3 weeks before the termination date
  2. The whole process can take up to 4-5 weeks.
  3. The termination date will be between Monday to Friday, during office hours.
  4. On the porting day, expect a downtime of up to a day if the other telcos have not updated their system with regards to the number being ported to Hoiio. We will try to minimize this downtime as much as possible but if it’s unavoidable due to the different schedules, each telco will follow-up with regards to updating their systems.

Contact information:

When you need help on number porting, please contact:

Hoiio Pte Ltd
Tel: +65 6602 8000

Tel:+65 6763 1111

Tel: +65 6714 6666