This thread is for general RPU usage questions. ---- Previous Thread was Specific GPU and RPU usage questions thread

Questions like "will my upgrade clear" are better placed in
[Consolidated] Chance of upgrade clearing on my flight [2016]
How often do your RPUs clear?

General comments on utility / value are better placed in
My new United Regional Premier Upgrade (RPU) strategy

Regional Premier® Upgrades (RPUs) are one-way, one-cabin, space available confirmable upgrades as early as the time of ticketing on eligible UA/UX and Copa Airlines-operated flights. They can be used on any fare and any flight that is also CPU eligible and on PS flights. This includes some Oceania and some COPA South America flights. They are generally not usable on flights outside of North America -- see upgrade region chart for details.

PS and non-west coast Hawaii flights are considered one of the better uses of RPUs since those flights are not CPU eligible and since elites are subject to copays on mileage upgrades.

RPUs are earned by elites -- (Re-)qualifying for Premier Platinum earns 2 RPU for the rest of the year, all of the next year and then thru 31 January of the following year. Re-)qualifying for Premier 1K earns 2 more RPUs and you can then earn 2 more RPUs for each additional 25K PQMs.
Unlike GPUs, UA does not offer an extension of unused and about to expire RPUs.

2MM, assuming they did not otherwise qualify for Platinum in the prior year, will have 2 RPUs deposited into their account around mid-January. 3MM+, assuming they did not otherwise qualify for 1K in the prior year, will have 2 RPUs and 6 GPUs deposited into their account around mid-January.

RPUs can be used for other individuals / friends / family but the upgrade priority is based on the status of the flyer, not the earning elite.

RPUs require PZ space (formerly R) to clear (except for GS RPUs which clear into PN space). For a given flight, RPU /GPU or Mileage+Copay have the same waitlist priority -- what does matter is passenger Status then Fare Class and then the time of the request. For more on waitlisting, see Understanding the United Upgrade List Comprehensively

A Regional Premier Upgrade will be considered used if any segment of an itinerary is upgraded and flown - no exception. Miles and GPUs have an exception if the waitlisted International BF/GF (now called Polaris business / first) does not clear, the miles/GPU will be returned -- this does not apply to RPUs. Recent changes in the rules make it clear there is no exception for PS routes.

Note on most RPU routes, a "connection" needs to be under 4 hours (longer only if it is the next scheduled flight) or a single RPU will not apply. This standard stopover definition for North American flights.

A single RPU (or GPU or Miles+copay) can not be applied to flights on different PNRs (or for different carriers even on the same PNR).