You're absolutely correct that I didn't address other risks when using a coupon broker (or, for that matter, any third party's miles). I was just responding to the characterization of all coupon traders being crooks.

I definitely would not describe such activities as "entirely safe."

As you point out, all the airlines do wield the power to refuse to honor tickets, cancel FF accounts, etc., if they catch you breaking their rules.

Your question limits the "safety" issue to when dealing with honest coupon brokers (vs. scammers).

At minimum, you have three links in the chain:

The coupon seller.

The broker.

The coupon buyer (who also is the passenger).

(It's possible the buyer and passenger could be different people -- e.g., you're purchasing the flight coupon for a friend or relative to use.)

If the broker is honest & capable, they'll know how to deal with the buyer, the seller, and the airline (making the reservation) discreetly.

The good broker also takes pains to qualify the seller -- know who the person is and how he accumulates his miles.

And the broker preps the seller: What to do in the unlikely event that a suspicious airline calls to ask about the flight coupon transfer.

And the broker preps the buyer: What to say if interrogated. (I don't recall anyone ever asking me any questions at all at the airport when I used someone else's miles.)

At this point, I can't avoid acknowledging that if interrogated, the only way to get what you're after (the seller wants money, the buyer wants a cheaper ticket) is to lie. So it's entirely valid for a critic to say, "It may be legal, but you might have to lie to do it."

Some people would avoid the possibility of such an encounter purely out of principle. That's laudable.

Some would avoid the possibility out of fear. That's understandable.

Some people would rationalize it in some manner:

"The airlines shouldn't prevent people from doing what they want with their miles"

or

"If the airlines were more fair in the way they set their fares, I wouldn't have to resort to such a measure"

or

"This airline has caused me so much grief over the years that it's only fair...."

Regardless of your rationalization, the truth is you might have to lie to an airline to complete such a transaction.

And, of course, some people have no problem at all with lying, under any circumstance. (But those people probably are not the kind you want to be involved with.)

So in the unlikely (but possible) event that the airline calls the seller, the seller needs to be both willing and prepared to lie: "Yeah, that's my brother-in-law, Dave, in Omaha. He's too cheap to pay his own way to visit us."

(The coupon broker has briefed the seller on the name & address of the buyer.)

Likewise, the buyer has been briefed about the seller. So if queried at the airport, the traveller knows to say, "Where did I get this ticket? My brother-in-law, Bob Whosis, gave it to me. Why?"

"Where does Bob live?"

"Huh? Well...He's in Nebraska. Just outside of Omaha. Why? Is that important?"

"No, no. Just checking...."

And, of course, it behooves the traveller not to blab about the arrangement to strangers.

My own experiences were a decade ago, always as a buyer, always with the same company (which, last I heard, still exists.)

I hasten to add that my transactions never involved United Airlines, so hopefully my disclosures here won't end up starting a UA investigation that jeopardizes my account. (As I mentioned in an earlier post, at a certain point I decided it was wiser to reap the benefits of highest elite status on one airline.)

The first time I used a coupon broker, I was very nervous about every aspect of the arrangement. Because that first time went smoothly, the broker employed real people who answered their own toll-free number, freely gave out their address, answered as many questions as I could think of, reassured me when necessary, and followed through on all their promises, from then on I called them whenever I wanted to use a broker.

I most often used them for international flights. My clients are responsible for my Business Class airfare. I would -- truthfully -- tell my client, "The lowest business class fare from my city to yours is ($7,500). If I use a coupon broker -- which is legal but against airline rules -- I can get a First Class ticket for $3,400. Which would you prefer?"

Oddly, they always preferred $3,400 to $7,500...And I flew First Class on the long journeys.

(But I didn't accrue miles, which is why eventually I deserted this strategy.)

The only time there was even the hint of a glitch was when, prior to a trip, I received a phone call from some security person for British Airways, located in New Jersey.

She was suspicious. Clearly trying to bluff me, she said something like, "You can't fly on this ticket."

I say "trying to bluff me" because I'm guessing she was hoping I'd panic, admit guilt, and throw myself on her mercy.

Instead I immediately became indignant and acted as any 100% legitimate passenger would:

"My hosts in London sent me that ticket. They said they're using the miles of one of their members, and they said it's all above-board and legal. Are you telling me it's not?? Because if I can't use the ticket they sent me, I'm not going. I've already been paid my consulting fee, so I'll let them sort out this ticket mess with you."

She immediately backed off, the flight went through without a hitch (except for an unbelievably rude BA flight attendant in First Class -- but I'll save my criticisms of BA's customer service attitude for another forum).

And that was the only time any problem even potentially arose.

I seem to recall I took a number of such flights on KLM, never a problem. (Using someone else's Northwest miles.)

Summing Up:

1. It's legal.

2. It's against airline rules.

3. It might require lying. (And that is the word for it, alas.)

4. With a good broker (one who's not a scammer and does know what he's doing) it's reasonably safe.

5. If you get caught, you definitely can expect to be denied boarding and you also might imperil your mileage account with that airline.

6. If you're the type of person who is law-abiding but enjoys "getting away with beating the system," you'll probably well-suited for it.

7. If you're the type of person who always is very respectful of authority and/or gets nervous in the face of authority, you might want to avoid it.