DS12 lost his birthday outing this year. He didn't misbehave to lose it, however. It was all about natural consequences.
His birthday was at the end of May, but the kids he wanted to invite were kids who attend summer camp with him, so we postponed it. The date was set for two weeks after the end of camp, and DS' job was to get the full names and phone numbers of the kids that he wanted to invite. (The place that he wanted to go to requires a release form, so we needed to send that paperwork directly to their parents and answer any questions that they had.)
Well, he dawdled, and he didn't bring pen and paper to camp until the last day to get the phone numbers. After getting them, he apparently laid the notebook down somewhere -- whereever he put it it wasn't in his bag. I picked him up as usual, 20 minutes before the teachers left for the day, and even asked him to double-check that he had everything because camp was closing down. We were a block from home (25 minutes away) when he suddenly piped up with: "I forgot the notebook!! I left it at camp!" I looked at the clock in the car and saw that it was 15 minutes after last lockup -- the teachers were all gone, and being as how it was the final day, they were not going to be coming back. It was simply too late. He didn't know the boys' last names, and this particular school would not release the phone number info to us in any case.
The outing was canceled. I was really sorry that it happened, as he had been talking about it for an entire year and was heartbroken, but I couldn't fix the situation for him. He messed up, and he had to take the consequences.
We don't do kids' birthday parties in my family. We've had one too many situations where not a single invited guest showed up, and we've decided that it just isn't worth it to risk dealing with that again. We will do outings, though; we find that offering to take a child on an outing at our expense AND transport him there and back tends to get a more reliable response.