My experience is that if they had that much trouble posting the miles, giving them back will be even more difficult for them. Only exception was that massive Goldpoints extra transfer a couple years back; they seemed to have fixed that on their own even though many of us advised them of the error. Also the extra Hilton points from that auto site quickly disappeared on their own.

I recently TWICE advised an airline they had only deducted the 80000 miles for my husband's ticket and none for mine; the second CSR actually said, "I won't tell anyone if you won't." It was obviously too much trouble for him to fix.

It happened to my only once. I got double credits for one segment of a 6 segment trip. It happened after asking CO multiple times to properly credit the trip. It took about 6 months to get the miles credited. Ifigured a 2000-miles excess is not worth the trouble for me or for them to correct. Besides it may take another 6 months to get all sorted out.

This may actually be a "sliding scale" situation.

If you found $5 on the ground, you most likely wouldn't bother trying to find a policeman or authority to turn in the money, right?

On the other hand, $500 or $5,000 would probably be enough money for you to think it's worth the trouble of turning it in, and you might do so.

But then again, if you found $50 million on the ground, would you turn it in, or would the temptation to run away and retire in paradise be too strong?

I got miles posted to my account one time for a flight I wasn't even on. I called the 800-number to let them know and the agent was so confused saying that no one had ever called to have miles removed. She said she didn't know how to take off miles posted by mistake, said "Merry Christmas," and that was it. Oh well... at least I tried.

PremEx has written that he has frequently asked to have non-flight miles removed from his United account. He credits partner points to other programs. That way he's able to say, when looking for an inventory exception while trying to claim an award, that all the miles in his account are from actually flying the airline.

I agree.

Does this work for him?

He reports that it does (or at least it did, when he posted this some years ago!)

OK, some have reported getting miles mistakenly posted to their account, for example, for flights taken by someone else unknown to you.

How about 12K+ flight miles (that's EQMs, folks!) and 10K+ bonus miles? Now we're starting to get into real numbers, and numbers that materially affect one's status! (Not to mention the earning of 500-milers and CR1s.)

Will an audit by the airline discover the mistake (and possibly kick you back into a lower status)? And just when might such an audit occur?

And if one notifies the airline of the error, are they likely to mess up the account in the process of trying to fix it, e.g., by removing upgrades that they shouldn't, and the like?

Anyone have answers?

After reading all the contributions to this thread, I just have to put in my 2C worth. I think you have to do what is comfortable for you. If you feel guilty about keeping something that doesn't belong to you, give it back. If you don't feel guilty about it, there's no need to justify it (because you can't), just keep it. There's no need to sugarcoat anything. We'll all mature enough to know there is a difference between what you should do and what you actually do. I don't think there is a "sliding scale" about how large or serious the mistake is, it is something that doesn't belong to you. If you decide to keep something that doesn't belong to you, just do it and get on with life. Don't make excuses or look for someone or something to justify what you did. I don't think there is a person alive who is 100% honest or 100% dishonest. Remember the saying: "You know what you did."

Uh-oh, here come the trolls.

No useful facts, just patronizing lectures.

Wow----you guys make me feel like a criminal

I would usually think that this type of situation is a no brainer, especially on FT but I guess saints exist everywhere. Honestly, I treat my account and the company as a "every man for themselves" type of mindset. Companies gift miles all the time for inconviences, it's no major loss out of their pocket per se.

In any case, I doubt that they will "debit" you. You took your time and effort to correct them on their mistake. Enjoy the compensation.

I've never had extra miles credited, but if there was a small mistake in my favor, I'd probably not bother with it. This is because I've not been credited for all miles due me for various promotions, but find it's not worth the time and energy spent trying to fix a mistake of 1-2K miles each time.

If it were a significant amount, I'd definitely tell the airline, whether it was in my favor or theirs.

1-2K is a lot miles for me. Heck, I've clawed for less than 100!

Well they never answered. And just do close the book on this, I finally
got a paper statement which listed two identical booking bonuses for these
flights. It wasn't threefold, as I had thought, it was just double. There
was another bonus that I had no memory of.

"Bank Error in your Favour, collect $20"