What's a kind way to bow out of an event that you're asked to volunteer for, without being offensive to the person requesting?

That sounds good, and maybe add a softener like “I hope it’s a good turnout, I look forward to hearing about it!”
Sounds more like involvement without obligation.

“I’m sorry, but something has come up and we won’t be attending the fair. Have fun!”

Had you previously committed to doing it? If you had and are bowing out last minute, than I think the explanation of a sick relative would be a more responsible way to bow out. If you hadn’t committed than yes to @Seek‘s suggestion.

“I’m sorry to miss it, we’ve had some unplanned family things come up that require my time.”

I can imagine that the person who heard your somewhat aversive excuse might be curious enough to ask why you can’t attend or is there any problem, then you’ll have to either spill the detail or lie to them. I think delegating the responsibility for the booth to other person should be at least considered.

Are you & the daughter both tied up on the day of the fair? If so, what’s wrong with the truth?

@stanleybmanly: Yes, we’re tied up visiting the sick relative.

Just tell them you will be unable to help out that day as you already have prior obligations.

Are they just asking for volunteers now – the day before the fair? That’s odd. If so, you have no obligation other than to say, “Sorry, but we have prior plans” as others have said.

it still isn’t clear to me whether you have previously said you would do it.

I would say, I’ sorry but we had a family emergency. (I say that because it’s tomorrow)

Thinking about this, it seems to me that while the date of the fair is specific, the visit to the sick relative is not date dependent ( I guess). You might be expected to “volunteer” for the fair, but if it’s not up to your taste, you should say so. Offer to bake, craft or donate something. It’s tough to determine from the question whether or not you would prefer any involvement with the event.

@jca “I am sorry. That will not work for me”. Nothing more is needed. No explanations necessary. AND, to ask why is rude!

“I do not work for free.”

~Pretend that you are possessed?

A simple apology is the best approach. No explanation is necessary.

@janbb: The email went out around Monday (today is Friday, fair is tomorrow). I hadn’t said I’d do it. The fair is a school fundraiser and probably 90% of the moms or dads volunteer.

In that case, “Sorry, we won’t be available to help out” should be sufficient.

I think you’re fine saying that you have a prior family obligation. Work the next event if you can, if that will help you to feel better. :)

What did you ed up doing? I didn’t realize they had use the “presumptive close” on you. If that were the case I would have no problem telling them that I wouldn’t be available. I would only have a problem if I had committed and were backing out.

I emailed the one asking for sign ups and told her we weren’t planning to attend. She responded “I understand. I hope you are well.”

I’m not particularly friendly with most of the moms in my daughter’s school. Not unfriendly with them, just not around much as I’m working and not into get togethers or play dates with the majority of them.

If you usually make it to events like this, and are a consistently reliable person, I don’t think you need to explain anything. If you already committed to it, then as soon as possible call up and say you unfortunately can’t make it, and apologize for any inconvenience to anyone. If you haven’t formerly committed just say you “won’t be attending the event,” you can add “because of other commitments” if you feel you have to.

You don’t need to explain, people should understand that sometimes we have our own personal lives to deal with.

If they are friendly with you their response should, “ok, hopefully next time.” Or, some sort of answer that makes you comfortable that you need to cancel. That’s the polite thing. It sounds like that is basically what happened.