What will cause the port-in process to be unsuccessful?

Here are some possible scenarios that will cause the port-in process to be unsuccessful,

• Outstanding amount not settled with your existing service provider
• You have an ongoing contract with your current service provider
• Your number is a supplementary line
• It is an inactive line
• It is a prepaid line
• The line is not registered under your NRIC/FIN
• The line is under corporate plan