[header] How to port a mobile number [title] Determine if your number is eligible for porting. [step] Prior switching to a new provider, make sure your current number is eligible for transfer. Check eligibility online with your old provider by entering your phone number and submitting a request. 
[substeps] If you are switching to at&t, navigate to its " transfer your number to at&t " web page. If you are switching to sprint, navigate to its " wlnp: check eligibility " webpage.