Only ZONE1511 subscribers with their mobile number registered are able to use the 1511CALLBACK service.
If you have not registered your mobile number/s with us, kindly login to your account via http://www.zonetel.com.sg
, click on “Manage Telephone Numbers
” to update your mobile numbers.
If you are not ZONE1511 member, kindly sign up at www.zonetel.com.sg. Alternatively, you may contact us at Corporate Helpdesk at 6720 6726 / 6720 6727 or email us at firstname.lastname@example.org