It’s not just that withdrawing cash costs money for Monzo, as they don’t actually own any ATMs is basically impossible for them to offer this service.
NatWest can only provide this service because they own their own ATMs. You can’t, for example, do this on a non-NatWest ATM.
One of the reasons that I moved to NatWest recently.
What brilliant idea
technically the service is not just on NatWest machines but on RBS Group machines. NatWest and RBS customers can access their emergency cash via each others cash machines.
That is going to be ideal for my upcoming trip to the Northern part of this Kingdom
There’s some Santander ATM’s locally to me that have a contactless point on them, I’ve never tried it but I think it does £20? Would be useful if this supported Android/Apple/Samsung/BPay/etc
£20 is a bit mean but for emergency cash (bus fare etc) better than nothing
I can confirm that Natwest also do this
No others do, as far as I am aware…
No, not just NatWest.
RBS, Ulster Bank, Isle of Man Bank, NatWest International, RBS International, Drummonds, all do so (and I assume Coutts, Holt’s, Child & Co and Adam & Co etc as they are in same group).
Cash is available thru not just RBS Group brands ATM but Tesco ATM too.
https://personal.rbs.co.uk/personal/current-accounts/shared-edb-shelf/shared-emergencycash.html
https://digital.ulsterbank.co.uk/personal/current-accounts/emergency-cash.html
https://www.iombank.com/iom/personal-banking/current-accounts/g32/emergency-cash.ashx
https://www.natwestinternational.com/nw/personal-banking/current-accounts/g32/emergency-cash.ashx
I’ve tried it. You can get any amount, I think. It’s contactless, but you still need your PIN.
Tbh I was only really talking about the “main” banks 
(Lloyd’s, barclays, HSBC, Halifax)
I have a Child & Co’s account and have the option through the standard RBS app.
Tesco ATM’s are administered by RBS Group hence why this works I assume.
I’m going to give TESCO a go later on
Actually feel quite pleased that the list is a long one
Having previously been an RBS customer i admit this was a great feature to have. It was also great if you needed to help a friend/family member out, you could just text them a code to pick up some cash.
But as has been pointed out above, Monzo would need to own a network of ATMs to do this. The best we can hope for at the minute is that more ATMs are upgraded with Contactless points so you could withdraw using Android/Apple Pay.