All three companies sell BYOP (Bring Your Own Phone) SIMs.SIMs for the AT&T, Verizon and T-Mobile networks are available from all three companies.
So if you have a phone whose home network is T-Mobile and you are in an area where T-Mobile has spotty coverage, the phone will refuse to roam on AT&T even if AT&T has a better signal. Which network a given Trac Fone, NET10 or Straight Talk phone is homed on depends on the market it's sold in.
Trac Fone companies seem to prefer selling T-Mobile homed phones, followed by Verizon with AT&T as a last resort.
The PRL is a list that allows your phone to roam off of towers that are not part of your native network, such as a sprint phone connecting to a former Alltel tower if none of its own are available.
Because roaming agreements are constantly changing and new towers are added all the time, it's important to keep this list up to date.
I suspect this is because they get the best deals from T-Mobile and the worst from AT&T.
What's most cost effective for Trac Fone is not always what's best for you as the end user.Here's how to tell which network a given Trac Fone is homed on and how to get a phone that will give you the best coverage in the areas where you live, work and play.Start by determining which of the three networks will give you the best coverage. And kicks me off of my video games or Hulu or Netflix.I Know you shuldn't drop it, but have done far worst with other phones with maybe a scractch. For most CDMA carriers (including Verizon), you can update your PRL by dialing *228 and selecting the appropriate option.