How to give cash at a wedding

[TheChaffinch]

Going to a nephew's wedding soon. They are a lovely young couple, it's quite a low key event and when I asked about gifts they said they didn't want anything.
It's true they have a home and everything they need but I would like to give money at least then they can buy something.
I don't really want to ask for bank details but I also feel just putting a few hundred pounds in a card it might get lost on the day.
Any suggestions as to how it's done?
I don't think I have such a thing as a cheque book any more.

My eldest DS got married four years ago, my younger DS last year and my eldest DD is getting married in a frighteningly few weeks. All of them had (or are having) a postbox for cards. My DD and her fiancee don't want gifts, they've got everything they need so I suspect they will be given money. I put my financial gift straight into my DDs bank account - if I wanted to give a substantial amount (say over £100) I would ask for bank details from the couple. If it was £100 or under I'd pop it in the postbox in a card.

We bought some nice gin for them and put the card (with cash) inside the drink bag, and let them know, it just felt safer than a card on its own, so you could wrap something small and pop the card inside the parcel.

You can actually lodge cheques via online banking apps now. You just photograph the cheque and upload