Originally Posted By: LED
Although I would think the 20 pound note a bit high for an emergency kit. Rarely do people have correct change during a crisis, so smaller notes are probably the way to go.
In the UK £20 is what the ATM machines dispense, so they are very common, and most vendors will accept them. They can probably give £5 or £10 in change. To put it in perspective, we don't have a £1 note at all. (£50 notes are very rare, and much harder to spend, but can be useful to get a lot of money into a small, personal cache.)

£20 is a reasonable amount if you want to pay for, eg a taxi home from town, or some petrol, or a meal for two. It's not really enough to pay for overnight accommodation, nor for a long train journey. £60-£100 is a more practical if you might get marooned somewhere other than your home town.

And some people keep emergency cash at home, too. You might need need to pay for urgent repairs to your roof.
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