To clear up any confusion and give you a Solid Answer, YES: Loading a Sprint handset into the PLBL ESN database does not require flashing, just an ESN load by the MVNO.
At activation time, Over-The-Air programming (OTA) will be performed to provision the handset (or manual programming if OTA fails), but this is not considered "flashing".
Now, not every Sprint MVNO has a policy of allowing you to activate your existing device on their network, but some do. There may also be a small charge for the loading of your device's ESN into PLBL which is sometimes billed as a separate charge at the time of the ESN load, or is bundled into the activation fee.
Here's how and ESN load is Done:
1. Provide the ESN DEC or MEID DEC to the Sprint MVNO of your choice. Do not provide the ESN HEX or MEID HEX as the Sprint network does utilize these (but Verizon Wireless/PagePlus/others do).
2. Wait a week (or longer).
Here's why you have to wait:
1. Sprint has a maximum delivery time for 3G handset ESN loads of approximately 3 business days, or 5 business days for 4G devices.
2. Sprint has a brand-new policy (as of March 2012) which is forcing MVNOs to submit ESN loads in lots of 20 at a time.
Here's what you need to be aware of before you pay to have your phone's ESN loaded by a Sprint MVNO:
1. If your Sprint phone is activated at the time that the ESN load is submitted, forget about the ESN load working because it will fail.
2. If you want to load a Sprint phone that has an ESN that is reported lost/stolen/insurance replaced, forget about the ESN load working because it will fail.
3. If the phone your are trying to get loaded into the PLBL belongs to an account that is in a non-pay/disconnect status at Sprint, the load will fail.
So the bottom line is the following: If you want to bring your own device to a Sprint MVNO, make sure you know that device really really well. If you bought it off of eBay, buyer beware.
So how do I know all of this? Well because, my company is a start-up Sprint MVNO !
And finally, here's some shameless self-promotion:
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