i just looked in my bag to answer that question, oldest one I have is for a biscotti and a drip coffee dated 2004. It was in one of those little front pockets though and I do have a gazillion handbags.
I go through my purse & wallet every week. I put all the sales receipts & refunds in a clear plasic folder/envelope.
When I've checked our bank statement/s, I then shred the ones I don't need anymore. The ones we need to keep for guarantees, etc., go in a small filing cabinet .