Editing Preferred Roaming List (section)

{{more footnotes|date=March 2015}}
The '''Preferred Roaming List''' ('''PRL''') is a database residing in a [[Wireless networking|wireless]] (primarily [[CDMA]]) device, such as a [[cellphone]], that contains information used during the system selection and acquisition process.  In the case of {{nowrap|1=[[Removable User Identity Module|R-UIM]]}}-based CDMA devices, the PRL resides on the [[Removable User Identity Module|R-UIM]].  The PRL indicates which [[Band (radio)|bands]], sub bands, and [[service provider]] identifiers will be scanned and in what priority order.<ref>{{cite web|title=PRL definition|url=http://www.phonescoop.com/glossary/term.php?gid=11|website=phonescoop.com}}</ref><ref>{{cite web|title=What is a PRL?|url=http://denbeste.nu/cdmafaq/prl.shtml|website=USS Clueless}}</ref>  Without a PRL, the device may not be able to [[Roaming|roam]], i.e. obtain service outside of the home area.  There may be cases where missing or corrupt PRLs can lead to a customer not having service at all.

On many [[cellular network|network]]s, regularly updating the PRL is advised if the subscriber uses the device outside the home area frequently, particularly if they do so in multiple different areas.<ref>{{cite web|title=How To: Update your preferred roaming list (PRL) on your CDMA device|url=https://www.androidcentral.com/how-update-your-prl-your-cdma-device|website=androidcentral.com|date=2010-10-27}}</ref> This allows the phone to choose the best roaming carriers, particularly "roaming partners" with whom the home [[Wireless carrier|carrier]] has a cost-saving roaming agreement, rather than using non-affiliated carriers.  PRL files can also be used to identify home networks along with roaming partners, thus making the PRL an actual list that determines the total coverage of the subscriber, both home and roaming coverage.

The PRL is built by an operator and is normally not accessible to the user. Many operators provide the ability for the user to download the latest PRL to their device by dialing an [[Over-the-air programming|Over-the-air]] (OTA) feature code. In the United States, for [[Verizon Wireless|Verizon]] / [[MetroPCS]] / [[US Cellular]], this feature code is *228 (*ACT).  For [[Sprint PCS|Sprint]], it is ##873283# (it is also possible to use code ##72786# on [[Android (operating system)|Android]] or ##25327# on [[iOS]] to completely clear out the service programming and redo OTA activation, which includes updating the PRL).<ref>{{cite web |url=https://www.reddit.com/r/Sprint/comments/2da7rk/you_can_update_your_phone_for_better_service_by/ |title=You can update your phone for better service by putting in this code. From 1x to LTE in my house!! : Sprint |date=2015 |accessdate=2016-07-19 |publisher=reddit.com}}</ref>  In Canada, for [[Telus Mobility]], the PRL update feature code is *22803 (*ACT03).