In the UK the word hash refers to this symbol: #
What symbol does 'hash' refer to in US English?
And what word is used to describe the '£' symbol?
US British # pound hash £ ? pound ? hash
The symbol # is most commonly known as the number sign,
[1]hash,[2]or pound sign.[3]
If I give my address as: 436 Main Street # 201, that is read "number".
If I add to my Facebook post #MeToo, that is a "hash tag"
If I write 5# of potatoes, I read it "5 pounds".
All of these are used in the US.
For £, I would probably say "Pounds Sterling" or "British Pounds" or something.
added
Request in a comment for reference on # for pounds ...
It seems to have been used only in America. Nowadays it is mostly gone, except occasionally for hand-written signs.
Lots of historical examples are found HERE
For example, this one dates from 1850.

At the top, 7-1/4 pounds of nails; at the bottom, 6 pounds of nails.
@choster I live in the US and I've seen the # called a hashtag both on Twitter and Facebook. As for the £ symbol, which is not included in the American computer keyboard, I heard of it as a pound sign on in finance language teaching books.
#defineand#includeunder C or C++, least 'round these parts. – tchrist Aug 16 '18 at 21:59