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I’ve got a thriving Award Booking Service. I hold myself out as an expert on the nuances of award-booking rules, and yet I don’t know United’s award booking rules. Let me explain.

On February 10, 2011, someone believed to be a United employee posted on FlyerTalk that the new routing rule for United awards would be that the actual routing you choose can exceed MPM by no more than 15%.

For those who don’t know: MPM (Maximum Permitted Mileage) is the maximum length that a routing on a paid ticket between an origin/destination city pair can be. City pairs with published fares between them have an MPM. For instance the MPM of SFO-SYD is 8,911 miles according to ExpertFlyer.

MPM is not the distance between two cities. For instance, San Francisco and Sydney are 7,417 miles apart.

That means a paid ticket between the two cities doesn’t have to be direct. SFO-LAX-SYD would fall well under the MPM. The FlyerTalk thread convinced everyone including me that United’s award rules allow an award to exceed MPM by only 15%.

Matthew at wrote a post saying this was the new routing rule on 2/10/11. Lucky agreed that was the rule on 4/29/12. Gary Leff agreed in a few posts, though on 6/10/12, he wrote, “After the merger with Continental was announced [United] increased it to Maximum Permitted Miles + 15%. The post-March 3 rules are a bit more opaque.”

I have parroted this MPM-plus-15% rule several times on this blog and to my clients. But there is currently no such rule–or at least it isn’t enforced by humans, isn’t enforced by the computer, and United agents don’t know what I’m talking about.

I can prove to you very simply that the computer doesn’t enforce the rule. The roundtrip price from San Francisco to Sydney with United miles should be 135k miles in business class. Indeed that’s exactly how this itinerary prices:

As you’ll notice on this award, oneway is direct: SYD-SFO. But the routing from San Francisco to Sydney is San Francisco-Tokyo-Bangkok-Sydney.

This circuitous routing checks in at a whopping 12,675 miles.

Remember that the MPM for SFO-SYD is only 8,911 miles meaning MPM + 15% is 10,247 miles. This flight path exceeds MPM + 15% by over 2,400 miles. This routing is MPM + 42%.

But is willing to let me purchase the award for the normal 135,000 miles. It sees nothing wrong with the routing!

So what is the real routing rule? As the post title indicates, I have no idea. has two pages with award routing rules. (Click on the rules next to a “+” sign near the bottom of the page.) One for awards on United, United Express, and Copa flights titled MileagePlus air awards, and another for partner award travel titled Star Alliance air travel awards. Neither page mentions maximum lengths for an award.

United agents won’t be able to tell you what the rule is, and it’s very important for trip planning. This isn’t just academic. Last week, I tried to book the following award:



That’s Boston to Marrakesh, Morocco, returning Malaga, Spain to San Diego with a stopover in Boston. Of course, this an award with a free oneway. Boston to San Diego was to be flown several months after the rest of the award.

This is a double open jaw roundtrip award with a stopover. So far that’s fine. From the rules on

Boston to Marrakesh doesn’t run into any MPM issues. Nor does Malaga to San Diego. The MPM from AGP-SAN is 7,304.

The route as flown is 7,540 miles, meaning it exceeds MPM by only 3%.

But the computer wouldn’t price the award, and agents, supervisors, and the rate desk all said that I could not ticket the award as constructed. (I cut BOS-PHX-SAN, and the award priced at 110k in business class as expected–60k for USA-Africa plus 50k Europe-USA.)

Apparently my award violated some rule, not listed on I don’t know what that rule is. Nor do I know what the United rule relating to MPM is (or whether there is any rule related to MPM on awards.)

As someone who tries to maximize my own and others’ awards, this is obviously a source of great frustration. United needs to clearly publish all its rules. Not doing so makes it impossible to fully participate in the MileagePlus program.

My best understanding of what’s allowed on United awards is what the computer prices–not what you can book online, which has more errors. If you call up an agent, give her the flights, and your award prices, it’s fine. If not, you can speak to as many supervisors as you want–don’t waste your time talking to the first line agent, she has no power–and you probably will not get your award ticketed for the right price.

What the computer prices is not entirely clear. The computer’s program is not an elegant, fully designed whole. Instead, it’s a mash up of changes related to the integration of Continental and United and the problems that created. That means that the computer prices some awards but not others with no discernible rhyme or reason.

To combat this problem, Tahsir and I have started telling our clients: “All these flights have space. A free oneway should be possible on this award, but I can’t guarantee United will price this award in accordance to the rules on its website.”

Will this affect you?

If you live at a major hub, the computer pricing issues will probably not affect you. If you add a one-segment free oneway to a simple roundtrip award, this will probably not affect you. The computer seems to be having the most problems with complex routings.


United does not have a rule that limits awards to MPM + 15% as widely believed. The exact rule related to MPM–or whether there is one–is unknown.

Other rules are also unknown. We don’t know what we don’t know. United needs to rectify this immediately.


To whet your appetite for tomorrow, the award in this post that costs 135k United miles costs only 110k US Airways miles. The commonly held belief about US Airways MPM rules is also wrong.

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