Both countries use the pound as their currency but generally you can't use Manx pounds in the UK but you can often exchange them at banks for free. UK pounds can be used in Isle of Man however.
Taken straight from the Royal Mint FAQ: "The Channel Islands and the Isle of Man are Crown Dependencies of the United Kingdom. They have their own legislative and taxation systems and issue their own banknotes and coins. These, in common with United Kingdom coins, bear the portrait of Her Majesty The Queen. However, they are only legal tender within the Crown Dependencies themselves"
the currency is the same (pound sterling) however the bank notes are different. Some places will accept the Northern Irish banks notes though many do not. You can take them to your local bank and get them exchanged to Bank of England notes.
The Isle of Man currency is "legal tender" only in the Isle of Man, and is not acceptable tender in Britain.
The Isle of Man currency (Manx Pound)(IMP) is pegged at par with the British Pound Sterling (GBP) and the Isle of Man decimal coinage, for the most part, resembles the dimensions, composition and history to the equivalent British Coins.
Yes you can, back in the UK shops may not accept IOM notes although I think they are swapped for free at most banks.
The Isle of Man uses pounds sterling. There is also the Manx Pound which is not accepted in the UK
The first Bank of England Twenty Pound note was issued in 1725. The first Bank of England decimal Twenty Pound note was issued in 1970.
The Bank of England first issued a regular Fifty Pound note in around 1725. The Bank of England issued the modern Fifty Pound note in 1981.
The Bank of England One Hundred Pound note was last issued in 1943 and ceased to be legal tender in 1945. The Bank of England has no current plans to reintroduce the One Hundred Pound note in the immediate future.
The Series "B" Bank of England (blue) Five Pound note was demonetised in 1967. The Series "C" Bank of England (blue) Five Pound note was demonetised in 1973. The Series "D" Bank of England (blue) Five Pound note was demonetised in 1991.
The Bank of England One Pound note was demonetised in 1988.
The Bank of England produced a Forty Pound note from 1725 to 1851.
The current Bank of England Ten Pound note with Charles Darwin on the reverse weighs 0.923 grams.
Englan pound
From 1992, the Ten pound note is mostly orange. From 1962 to 1991, the Ten pound note is mostly brown. Prior to 1962, the Ten Pound note was white.
The Bank of England issued the last One Pound note in 1984, then withdrew and demonetised the One Pound note in 1988, after it was replaced by the One Pound coin in 1983.
The building on the reverse of the Series "A" One Pound note, is the Bank of England building as it appeared in 1928.
The first ever Bank of England Ten Pound note was issued in 1759.