Have this on lock screen (party)
The vouchers do not expire, at least mine don't. I've got the same ones from June last year.
Always keep a voucher in case they ask but they don’t look at it and the date if you have it folded up
Those machines dont give out a receipt most times in my experience. Few times I got caught out. I just told them I lost it. They give it to me anyway. But I've learnt to keep a voucher just in case.
All year round