The Scottish banks have to have their banknotes backed by Bank
of England notes, and for this purpose the Bank of England has
issued notes for GBP1 million and GBP100 million.

The highest denomination banknote that I have ever seen issued was for
$100,000, bearing the portrait of late US president Woodrow Wilson.

It's mentioned on this page.
http://www.bankofengland.co.uk/bankn...ther_notes.htm
I like the point that the GBP1 million and GBP100 million notes are
'not for general circulation.'

Neither were the $100,000 US ones. The largest US denomination for
general circulation is the $10,000, last issued around 1944 (but still
valid if you have any, as the US does not demonetize old issues).
The highest denomination still printed in the US dropped again around
1969 from $1,000 to $100, and Canada copied that move in about 2000,
in both cases on the grounds that criminals would be inconvenienced
and most other people would not.

ObRail: a few years ago in Switzerland I had the pleasure of buying
a train ticket that cost something like 130 francs and paying for it
by inserting cash into the ticket machine *including a 100-franc note,
worth over 40 pounds*. The 200-franc denomination was in common use
as well, and I daresay the machine would have accepted that too if my
ticket had been expensive enough.
--
Mark Brader | "But [he] had already established his own reputation
Toronto | as someone who wrote poetry that mentioned the el."
| --Al Kriman

My text in this article is in the public domain.