Do you have insurance on classes???

Well isn't this interesting news.  The nonprofit puts on a major event and they want you to show proof of insurance  AFTER the end of the convention????

This issue is professionally covered in the "vendor" category of exhibitors for professional conventions.  They advise you upfront BEFORE the event, whether they require insurance. Then you can choose to buy or otherwise provide proof.  But you usually have to provide the proof BEFORE your booth registration is processed BEFORE the event.

If your nonprofit didn't advise you in writing of their requirement for you to prove insurance BEFORE the event, then they cannot pull this lame excuse after the fact.  Better to write off this bill as a "donation" and simply not teach for this outfit again. Next year if somebody asks, just say "I don't have insurance"...

I'm sorry, I am aware that a large class costs $$$.  I suggested the write-off based on the fact that you want to keep some decent relationship with this nonprofit.

But I seriously think they did something very stupid.  THEY have the obligation to see proof of insurance BEFORE the event for the sake of the attendees. Asking for it some weeks after the event just makes them look like they are too cheap to pay your request for reimbursement.  You should not need to submit receipts because you may have split a shipment with somebody else. 

Is there any way that you can contact senior management about this specific requirement? Can you resubmit a written "request for reimbursement" and cc the president?  And because it is your second request, you would also ask for a response in writing.  Then you would simply forward the written refusal to that officer for corrective action.

You see, a nonprofit that treats its good and generous people like this is not going to survive for long.    

If I make any purchases (ingredients, hand tools, etc) and will be reimbursed, I always keep receipts and submit them with an itemized bill. As for teaching, I hold classes and workshops and do not carry my own insurance. The business, school, organization, or non-profit that sponsors my class is responsible for insurance. Whoever you're dealing with sounds like a scoundrel.